Abstract:放。In view of high cyclic variation and HC emissions of the lean-burn gasoline engine at idle conditions, an experimental investigation was carried out on a gasoline engine equipped with an electrical controlled hydrogen injection system. The hydrogen volume fraction in the total intake of 3% was adopted through adjusting hydrogen injection duration to study the effect of hydrogen enrichment on combustion and emission characteristics of a lean-burn gasoline engine at idle. The test results demonstrated that the indicated thermal efficiency was improved; flame development period and rapid burning duration were shortened after hydrogen enrichment. When the excess air ratio was 1.3, the coefficient of variation in indicated mean effective pressure was dropped from 33.9% of the original engine to 13.7% of the 3% hydrogen-enriched engine. Under idle and lean conditions, the addition of hydrogen was effective on improving HC, CO and NOx emissions performance of the SI engine.

Abstract:In the spray turbulent combustion, droplets, turbulent and chemical reaction are strongly coupled and the physical and chemical mechanisms are very complex. Velocity-scalar-frequency joint probability density function (JPDF) transport equation method was introduced into the two-phase turbulent reactive flow coupled with flamelet method for solving the relation between flow field and chemical dynamics. Based on this model and the Monte-Carlo numerical solving method, the numerical simulation was performed for the turbulent spray combustion in a piloted jet flame burner developed by Masri. The comparison between the experiment and the numerical simulation results verified the spray JPDF model.

Abstract:The research on factors affecting injection quantity fluctuation for main injection was performed. The experiment was conducted by measuring the fuel quantity and flow rate for pilot and main injection with EFS IFR8420. The factors influencing were given as follows: main injection quantity fluctuated remarkably with short dwell time and small pilot injection quantity, with increasing dwell time between pilot and main injection, main injection quantity fluctuated periodically and the fluctuation range attenuated gradually. It is concluded that the injection quantity fluctuation is caused by the fluctuation of rail pressure generated by the pilot injection. 

Abstract:Based on steering kinematics and dynamics analysis of tracked vehicle, steering control strategy was presented to realize reducing average vehicle speed automatically while achieving the driver’s expected steering radius exactly in the case of not exceeding the system pressure threshold and secure steering. The steering controller was comprised of neural network PID controller and pump & motor displacement controller. The steering neural network control simulation was conducted by using Simulink of Matlab. The simulation results indicated that compared with conventional PID control, neural network control export overshoot reduced from 10.5% to 4.1% and control response time decreased from 4.8s to 2.2s, which meant that system real-time ability and robustness were improved. The simulation results for various steering conditions demonstrated that good steering stability and maneuverability were obtained with neural network control for tracked vehicle with hydrostatic drive.

Abstract:A 2-D load spectrum program based on rain-flow counting method was compiled in Matlab environment. The program was used not only in statistical treatment of load time history of motor propulsion system on hybrid electric vehicle (HEV) and getting rain-flow matrix, but also in hypothesis test for both amplitude and mean value distribution. 2-D distribution function was obtained after the independence and relevance tests of the amplitude and mean value. 2-D load spectrum was set up for traction motor propulsion system on HEV used in bench experiments.

Abstract:The no-rationality of the optimization of power matching on torque-converter with diesel engine for wheel loader was analyzed. Based on the hydraulic pump in accordance with the work of loaders, the loader was divided into three typical operating conditions. The satisfactory degree function in the optimization of power matching on torque-converter with diesel engine based on the generalized satisfactory degree theory was explored. Multi-objective optimization design of power matching on torque-converter with diesel engine was introduced, and the problem-solving steps and methods were given. The analysis shows that this method can improve the quality of the power matching.

Abstract:Based on the continuity and motion equations of fluid, the velocity potential functional equation of the S1 stream surface and the velocity gradient equation of the S2 stream surface were established. The flow field of the direct problem was solved by calculating the two families of stream surfaces. Based on the flow field of the direct problem, the inverse problem of centrifugal pump in drawing blade shape by point-by-point integration, thickening blade and smoothing leading edge of the blade by conformal mapping was accomplished. By using the flow field of the direct problem calculated by the impeller of the inverse problem to design the impeller, and using the impeller of the inverse problem designed by the flow field of the direct problem to calculate the flow, the final impeller was designed when the direct and inverse problems was converged. This method which applies the meridional velocity of direct problem result to inverse problem, can make up the deficiency of traditional design method by using one-dimensional flow assumption. The final impeller can distribute load equally with the characters of high efficiency and excellent cavitation performance. This method can increase the efficiency of design work and the accuracy of calculating results. The data of the blade’s surface is complete which is convenient for blade manufacturing by numerical control machine.

Abstract:Based on the design of low specific speed submersible pump, the influence of impeller structure parameters on shaft power of pump was analyzed. Under the condition of the maximum value of shaft power being no more than the input power of matching electromotor, the method of reducing the maximum value of pump was further researched in order to reduce the power of the matching electromotor. Then the design discriminated formula of the structure parameters of impeller was presented. The value of shaft power was predicted by the Fluent software. The results indicated that the ratio of maximum power of pump to the power in designing condition was less than 1.2 when the presented discriminated formula was used in design. The results of the experimentation of prototype showed that every parameter met the rating requirements; the maximum value of shaft power of pump was reduced greatly. The results demonstrated the guiding role of the discriminated formula in practice.

Abstract:The influence of interstage leakage among impellers to the flow state outside the front and back shrouds of the multistage centrifugal pump was studied. The velocity distribution of inner flow and the value of axial force were measured by the experimental device of centrifugal pump. The results indicated that the rotation velocity of the liquid outside the front shroud was 0.5 times larger than the angular velocity of impellers, and the velocity outside the back shroud was 0.5 times less than the angular velocity. The pressure outside the front shroud was lower than the value outside the back shroud. The actual value of axial force was lower than the calculated. And the formula of the axial force should be modified. 

Abstract:The simulating test is the important means and method to reduce cost and raise efficiency of new type of farm machinery design. According to the actual working circumstances of farm machinery in the paddy field, a trial soil bin which could imitate actual work in field was designed. The project and process of the soil bin design were introduced briefly. The methods to resolve the problems such as how to make the wet soil and how to control the water content of soil were proposed; based on the analysis of the functions and characteristics of the soil bin, experimental data sampling system was developed. 

Abstract:The lug is the basic element of a paddy-field lugged wheel. Soil flowed under the lug develops the pull and lift forces on the lug. In a set of specially designed soil box, the soil flow under the lug was photographed and the soil reaction forces on the lug were measured. Firstly, soil flow track, flow mode and flow zone under a lug were studied. The effects of the pull force, lift force and driving efficiency and their relationship with the soil flow in the interaction between the soil and lug were analyzed. The cause of low driving efficiency was further studied for the lug with slip and deep sinkage. 

Abstract:12.04%。The infrared detecting system was hard to work well in short detectable distance and complex circuit. The double-infrared emission was adopted for improving the optical path and increasing the receiving area. The optic circuit of infrared detecting system for automatic target spraying was also improved by changing the whole detecting device into separated parts, by which increased portability and transferability of infrared detecting system for automatic target spraying. Test results showed that the detection performance increased by 48.96%, sensitivity of the space between two spraying targets increased by 12.04%.

Abstract:The effects of land use structure on the spatial variation characteristics of soil water content were studied based on the survey of soil water condition on a cropland-grassland mixed slope land in the Loess Plateau. The results showed that the soil water content presented a moderate spatial variability on the slope scale. The cropland-grassland mixed land use structures significantly increased the spatial variability of soil water contents. The soil water content had obvious spatial structure. The Gaussian model and Spherical model were the best fitting descriptors for the mean soil water content of 0～60cm soil depth under arid and moist condition respectively. Compared to the moist condition, the mean soil water content had a higher sill and range, but a lower nugget-to-sill ratio under dry condition. The interpolation map by Kriging method showed that soil water content presented a significant different plaque distribution pattern, which was consistent with the mixed land use structure on the slope. The difference in the spatial variability and distribution pattern of soil water content (0～60cm) in the test area mainly were effected by topography, precipitation, land use and land use structure. 

Abstract:One-dimensional perpendicular infiltration process to water with different mineralization degree by uniformity earth pillar experiments was studied. Soil moisture content distribution and infiltration rate infiltrated by different mineralization degree were analyzed. The variance in regular pattern of soil profile salt content as well as desalt depth after infiltration in response to mineralization degree of infiltrated water were carried out at the same time. The results showed that saline water infiltration could transform soil structure and enhance both soil water transmitting ability and moisture holding capacity, but in company with sodium ion in soil increasing, soil water transmitting ability and moisture holding capacity did not depend only on mineralization degree, but rather codetermined by both mineralization degree and sodium ion quantity; top soil salt would be infiltrated by water when mineralization degree lowered about 3g/L, but soil salt was scarcely infiltrated when mineralization degree further increased.

Abstract:In order to research the difference between continuous infiltration and intermittent infiltration of fresh water and saline water, one-dimensional infiltration experiments of continuous and intermittent water with salinity of 1.33g/L for fresh water and 3g/L for saline were carried out in clay soil. The results showed that saline water can influence soil structural characteristics and enhance infiltration capacity. One dimensional infiltration modeling analysis showed that the model is able to describe the process of saline water infiltration exactly. Intermittent infiltration of fresh water had an effect of reducing infiltration, however, intermission infiltration of saline water had an effect of increasing infiltration. There existed slight difference in infiltration-reducing and infiltration-increasing effect for various circulation rate of intermission infiltration.

Abstract:A research was carried out to determine the aftereffects of rewatering after water stress in the final rice growth stage by pot and test-pit experiments. The results show that the post-drought rewatering has obvious aftereffects in the initial rice growing stage, which is particularly significant after short-duration heavy drought at late tillering stage and light drought at early jointing stage. Moderate rewatering after water stress in initial rice growing stage can preserve large photosynthetic area, delay chlorophyll degradation, enable functional leaves to maintain high photosynthetic efficiency, which is eventually beneficial to dry matter accumulation during final rice growth stage. 

Abstract:The filter in micro-irrigation is the key to guarantee normal running of the whole micro-irrigation system. It is the key to develop automatic filter. Based on the research of hydraulic performance of drain system for automatic suction screen filter, the discipline of filtering time for automatic suction screen filter was analyzed. It showed that the change of filtering time was not linear. The factors affecting sewage time were analyzed. The results showed that the cleaning-time was not the constant value, but had the inverse relation with inflow sediment concentration S0 when other parameters were constant.

Abstract:The influencing factors such as fire, soil moisture, organic matter, soil pH value, biology film, clay mineral etc. and the amelioration of soil water repellency and the research progress were mainly discussed. Meanwhile it has been pointed that the further study should be focused on the research of soil pore or particle-scale, expressing the relationship between water repellency and soil moisture, quantifying the various hydrological effects of water repellence at large field scales. The future research orientation on water repellency in China was also pointed out.

Abstract:In Shandong Province, water shortage is the most important problem for winter wheat production. Four planting patterns, i.e., uniform row, “20+40” wide-narrow row, “20+40” furrow planting, and “20+40” bed planting patterns which were widely used in Shandong Province were selected for the experiment to study the effect of planting patterns on water use efficiency (WUE) and marginal profits of winter wheat. The results indicated that the max yield of uniform row, wide-narrow row, furrow planting and bed planting were 7778.6, 7624.8, 8684.6 and 8893.7kg/hm2 respectively. But, if get the max yield, evapotranspiration of bed planting pattern was higher than that of furrow planting pattern by 76.6 mm. The max WUE of furrow planting was lower than those of uniform row and wide-narrow row planting, so did bed planting. But if get the max WUE yield and evapotranspiration of furrow planting pattern was 7858.8 kg/hm2 and 407.5mm respectively, they were all significantly higher than those of uniform row, wide-narrow row and bed planting patterns. Take the water resource use efficiency and marginal profits as a whole, furrow planting pattern irrigated at jointing and heating growth stages could get the highest netincome, under these conditions, yield was 8186.3kg/hm2, irrigation amount was 120mm, evapotranspiration was 423.5mm, and WUE was 19.3kg/(hm2?mm). The experiment showed that under water deficit, furrow planting was the most appropriate planting patterns in Shandong Province. 

Abstract:Based on the analysis on the force and movement of biomass materials extruded by screw molding machine, disassembling the whole screw into the screw head and the main screw body, the molding sleeve into forming looper and Paul-type sleeve, and optimal design of the parameter of screw head which contains spiral leaves diameter D, blade pitch S, screw shaft diameter d, and the sleeve data was carried out. The tests showed that changing the screw head and forming looper was able to reduce the wear, the service life of the screw head and the main screw body was up to 90h and 1000h respectively, biomass briquette production was increased, production efficiency compared with the original machine increased 66.12kg / h. The optimal design promoted the applications of biomass briquetting machine.

Abstract:Pretreatment of corn cob was carried out by microwave/alkali and microwave/acid, including different power densities and time of microwave pretreatment. The results showed that average weight of reducing sugar received by microwave/alkali pretreatment was 51.71mg, over 33.82% than the control. And the weight was 8.76mg by microwave/acid. Acid/alkali pretreatments were followed by microwave treatment. Average FPA activities were 2.23U/mL and 10.90U/mL in fermentation fluid, respectively, increasing 35.05% and 17.26% compared with the control. Meantime average CMC activities were3.43 U/mL and 12.41 U/mL, respectively, decreasing 15.96% and increasing 34.32% respectively compared with the control. Alkali pretreatment of corn cob followed by microwave was better than the acid pretreatment.

Abstract:，能耗降低55.86%。The overall structure, working principle and design points of microwave vacuum freeze drying equipment were described. A detailed analysis on microwave syntony cavity, microwave shielding structure and the design of glass vacuum cover was made. The specific structure and related parameters of main working parts were determined. The study on freeze drying of winter Chinese date showed that the equipment had the characteristics of rational structure, stable performance, and safe and reliable running process. Compared to the ordinary vacuum freeze-drying technology, it could produce the same quality product while saving 40.9% drying time and 55.86% energy. 

Abstract:A hybrid solar drying system assisted by heat pump for grain in-store drying was developed. The system is composed of solar air collector, heat pump and stir machine for grain. The experimental study was conducted for maize drying. The results indicated that average thermal efficiency of the air collector is up to 63% and COP of the heat pump can reach 5.4. The combined system can supply adequate and stable thermal energy. The effect of drying is obvious. Drying time is reduced and energy consumption is low. Besides, the uniformity of moist content is improved. Utilized for maize in-store drying, the system can reduce the moisture content of maize in the granary with the characteristics of safety, energy saving and better effect.

Abstract:With 3% O2 concentration, effects of different CO2 concentrations on fruit quality, post-harvest physiology and tissue browning of ‘Whangkeumbae’ were investigated by using accurate CA match air equipments during shelf-life days. The results showed that different treatments of controlled atmosphere (CA) could delay declining of fruit firmness. Furthermore, under the treatment at CO2 concentration of zero, the fruit respiration rate and polygalacturonase (PG) activity were obviously inhibited by CA and there were no browning reaction on the pericarp and pulp with high firmness and good flavor of fruit after 180 days storage. Under 0.5% CO2 concentration treatment, there was light pulp browning. According to the experiment, 3% O2 and CO2 concentration of 0~0.5% was optimal condition for CA storage of ‘Whangkeumbae’. ‘Whangkeumbae’ pear is sensitive to CO2. When CO2 concentration was more than 1% the fruit browning were more serious with increasing of concentration of CO2. The results also indicated that PPO activity and the content of ethanol were important factors of browning reaction in ‘Whangkeumbae’ pear. 

Abstract:Change of the linear relationship between CT value and major internal components of Fushi apple during storage period was discussed. CT images and CT value were acquired by scanning the section of Fushi apples, and the model of linear relationships between CT value and major internal components was established. The linear relationships in different storage time were compared. It’s clear that the pH value and sugar content increased with the growth of storage time, while moisture content and titrable acidity decreased. The linear relationships have been changed during the storage period. So the storage time was introduced into the predicting model, which was used to predict the internal components of Fushi apple. The predicting model was proved to be accurate and feasible.

Abstract:In order to discuss the effect of two types of high voltage electric field treatments on the storage quality of tomato fruit, “Zhaoyan219” tomato was taken as the experimental material, and the two treatments of the negative high voltage intermittent electrostatic field (namely steady electric field) that was 200kV/m and 2h/d and alternative electric field pretreatment (namely alternative electric field) that was -200～200kV/m, 40kHz and 2h on the effect of qualities of mature green tomato fruit during the storage quality(13℃) were studied. The results indicate that the two treatments can lower the decay incidence (P<0.05) remarkably. The decrease of firmness of tomato fruit, the content of soluble sugar and chlorophyll content of tomato peel and the increase of titratable acid and lycopene content are postponed by the effect of high voltage electric field treatments. That is how the infirmness is delayed and the qualities of tomato fruit are improved. 

Abstract:In order to determine the impacts of natamycin on postharvest asparagus, respiratory rate, color, shear force, weight loss, free polyamines, bacterial and mold count were examined under low temperature. The results indicate that the natamycin treatments reduce respiratory rates of asparagus, inhibite the increases of weight loss and putrescine content, and cut down the total molds of 1~3 orders of magnitude effectively. The peaks of spermine and spermidine appear earlier in natamycin treatments and their contents are increased. Moreover, the asparagus with natamycin has better appearance and texture.

Abstract:Pd/C catalysts was prepared by impregnation and the variation of soy lecithin’s iodine value after hydrogenation was studied. The characterization of catalysts was analyzed by using microspecrtoscopy (TEM). The results showed the optimum preparation condition was as follows: when carbon was pretreated with 10% HNO3 solution, impregnated 2h in 3.5mg/mL H2PdCl4 solution at 40℃, then reduced 5h in 30% formaldehyde solution at 80℃, solution pH value 1～2, Pd/C catalysts were dried in 80℃ vacuum condition. The Pd particles size was 7.8nm. After Pd/C catalysts hydrogenated, soy lecithin’s iodine was down to 18.6gI/(100g). The results showed solution pH value effected catalysts activity largely. The smaller Pd particles size was, the stronger catalyst activity was.

Abstract:1/2。The combined dynamic countercurrent extraction equipment by microwave and ultrasonic-wave was investigated. The structural composition, working principle and technical characteristics of the equipment were introduced. The experiment of extracting more effective components of tea with the combination dynamic countercurrent extraction process by using microwave and ultrasonic-wave was tried with setting water as solvent and fresh tea leaves as raw materials. The rate of extracting effective composition in tea by using different extraction powers, extraction ratios of solid-liquid and extraction time were investigated. And the extraction process was optimized by L9 (34) orthogonal experimental design. The experimental results showed that the optimal extraction process parameters of the device were extraction time microwave 6 min + ultrasonic-wave 6min, solid-liquid ratio 1∶20, extraction power microwave 1.0kW + ultrasonic-wave 1.0kW. The extracting rate of tea polyphenol, amino acids and caffeine was higher than the normal extraction, and the extraction time, the extracting times and the extraction temperature were 1/5, 1/2 and 1/2 of the normal extraction, respectively. 

Abstract:BHT和GBE（P<0.05）。 The extracting technology and antioxidant activities of lotus leaf were studied. The results showed that the optimal parameters of the extracting technology were the extracting time was 50min, the extracting temperature was 80℃, the concentration of ethanol was 60% and the ratio of sample to extracting solution was 1∶20. The ethyl acetate fraction possessed the strongest antioxidant activities (P<0.001or P<0.01), i. e., the reducing power, FRAP value and DPPH radicals scavenging capacity among the four increasing polar fractions (hexane, ethyl acetate, butanol and aqueous fractions) through the bio-assay guided method. The OD593 values and DPPH radicals scavenging capacities of this fraction were better than those of the positive controls of BHT and GBE (P<0.05) through the experiments of verification. 

Abstract:Arg-Val-Pro-Ser-Leu-Met、Thr-Pro-Ser-Pro-Arg和Asp-Leu-Gln-Gly-Lys。Antihypertensive peptides were derived from egg white, and then were purified and their primary structure was identified. Egg white hydrolysis process model was established by examining the substrate concentration, E/S, hydrolysis temperature and pH value on the impact of the hydrolysis degree, combined with multivariate linear regression combination of design and quadratic regression orthogonal design. Hydrolysates were purified by gel chromatography, and were characterized by liquid chromatography tandem mass spectrometry. The results showed that the optimal enzymatic hydrolysis process was the substrate concentration of 8%, pH value of 10.73, E/S of 12.14% and temperature of 56.80℃. Hydrolysates were purified by sephadex G-25,the 50% inhibitory concentration as 0.18mg/mL.Liquid chromatography-quadrupole-linear ion trap tandem mass spectrometry confirmed the structure of the active peptides in the component, the amino acid sequences were Arg-Val-Pro-Ser-Leu-Met, Thr-Pro-Ser-Pro-Arg, and Asp-Leu-Gln-Gly-Lys, respectively. 

Abstract:Based on the GPS technology and the embedded system, a multifunctional agricultural aircraft navigation system was designed. It combined the functions of automatic depiction of the farm outline, automatic trace planning, farm area calculation, real time trace-display and voice prompts. System hardware platform and QT environment were introduced, and the system function algorithm was discussed. The least square method was used to predict the positioning data in high-speed environments, it effectively reduced the positioning delay generated by the high-speed motion. Designing functions were achieved with the navigation system in certain field.

Abstract:The mathematical model of the variable rate fertilization control system according to the principles of mechanical and electrical dynamics was set up and the theoretical basis for the system design, parameter selection and performance improvement was provided. The simulation model with direct current servo motor driving variable transmission mechanism was constructed by using Matlab/Simulink dynamic simulation tools. PID parameter tuning of control system was carried out by the critical proportioning method, the simulation curves of system performance was obtained. The simulation results showed that PID control strategy could improve the control system tracking performance and anti-jamming performance, and the test was carried out to verify the system performance.

Abstract:150ms。To improve real-time performance of agriculture vehicle navigation, an algorithm based on least square method for detection of crop rows, especially of crops in the early stage of growth was proposed. Crops were segmented from background by the index of G-R. Parts of the noises of weeds in the image were eliminated according to their length. Crop line numbers were detected dynamically by vertical projection method. Center points of crop rows were extracted as feature points and were classified into different clusters. Least square method was used twice for fitting the center line of crop row to the feature points. The number of the feature points was counted to judge the reliability of the detection result of crop row with plant deficiency. The experimental result showed that the algorithm could overcome the effect of weed noise and plant deficiency. The average time of image processing was less than 150ms.

Abstract:100%、91.4%、88.9%和76.8%。The area and wide length ratio was chosen as the characteristic parameters for different kinds of rice seeds, and a database of rice seeds type was constructed. The equivalence rectangle’s length and the least wide difference were used as standard to identify unknown rice seeds type. The disrepair of the rice seeds was identified based on the times of the black pixels change to the white pixels on one scan line and the number of scan lines. The mildew of rice seeds was identified based on the difference of area obtained by two different thresholds. Ten kinds of rice seed samples like Fengyuanyou 299 were chosen for the experiments. During the experiments, inspection of seeds type, identification of seeds in work positions, geometry parameters of seeds, mildew and disrepair situations of seeds were done respectively. The accuracy was 100%, 91.4%, 88.9% and 76.8% respectively. 

Abstract:Electromagnetic induction (EM38) and variance quad-tree (VQT) were both applied in the field of the coastal reclamation area in north Jiangsu Province. Apparent soil electrical conductivity (ECa) measured with EM38 was used as an ancillary variable of soil salinity, and the spatial distribution of ECa was used as priori information. The optimized sampling pattern of soil salinity was designed and validated by using VQT method, and the precision of the sampling design was evaluated. Results showed that the kriged spatial distribution map of the VQT scheme was highly similar to the kriged map of total sampling sites, while sampling quantity of the former was almost 1/2 of that of the latter. With the same sampling quantity, the kriged map of VQT scheme was more similar to the kriged map of total sites than that of grid sampling scheme. With the same mapping accuracy, the sampling quantity of the VQT scheme was less than that of grid sampling scheme. Under the condition of permitted maximum difference index of 10%, the sampling efficiency of VQT method could be improved by 17.3%.The advantage of the VQT method was that the scheme sampled sparsely or intensively in terms of variability in local parts of the study area. The associated application of EM38 and VQT method provided efficient tools and theoretical basis for saving cost and improving efficiency in coastal saline region. 

Abstract:Based on wireless sensor networks, a greenhouse environment monitoring system was designed to deal with problems in current greenhouse monitoring system, such as complicated cabling, high energy consumption, limited transmission distance, and inflexible deployment. With SoC of CC2430 and ZigBee protocol, environment information was collected, self-organized networks were realized and aggregated monitoring data was collected by the wireless sensor node. Gateway hardware platform was structured based on the S3C2410A microprocessor, and WinCE5.0 operating system was chosen as software platform. A gateway management system was developed on embedded database for sensor node administration, data processing, and early warning of weather disaster. Preliminary experimentations showed that the system met the application requirements of greenhouse monitoring system excellently, and had the advantages of low power consumption, inexpensiveness, flexibility, extensibility, and friendly human-machine interface.

Abstract:In order to reduce the adverse impact of network time-varying delay, packet loss, network congestion, jitter and other properties on performance of the monitoring and controlling system for greenhouse environment based on wireless sensor networks, the event-driven feedback scheduling strategy was proposed. The basic idea of the proposed event-driven feedback scheduling strategy was to use deadline miss ratio as the indicator for the network quality of service, adjust the sampling period of each sensor nodes by means of feedback control technology at run time such that the bandwidth requirement of each sensor nodes could adapt the change of the network workload, and the quality of network service could be maintained at a certain level. The novel event-driven invocation mechanism for the feedback scheduler was adopted to reduce the design difficulty and overhead of the feedback scheduler. Experiments indicated the proposed event-driven feedback scheduling strategy was with rationality, effectiveness and practicability.

Abstract:The layout model representation method based on space partition method was established to solve the 3-D mixed layout design. Linear octree and raster data model were used in conversion model for corresponding cylinders layout objects and cuboids layout objects respectively. The filled ball group was proposed for the layout model representation method, and on this foundation, the mathematical model of the layout optimization problem was obtained according to the layout design requirements. Then the TSP problem was transformed into the layout design problem by establishing directed layout sequence. Meanwhile, the fitness function was applied to deal with the multi-objective optimization in the course of the layout, and the improved ant colony algorithm was put into use to gain the Pareto optimum. At last, the effectiveness of the layout method for modeling and optimization algorithm was illustrated by the comparison of the layout design schemes.

Abstract:A flexible modular division method was proposed to the reconfigurable machine tools （RMT）considered the influence of customer demand, the structure-function and life cycle effect. Analytic hierarchy process (AHP) was used to weight the different influence factors and the interaction among the machine tool parts and the related matrix were obtained. The fuzzy clustering method was used to operate the matrix. The control system was modular divided based on the specialty of RMT. The proposal for RMT modular division was obtained and could be used as the foundation of RMT developing. 

Abstract:For traditional machine, to modify spiral bevel gear tooth-profile lengthwise curvature, cutter must be disassembled and adjusted its diameter. This is a complicated process. On domestic-made 4-axis CNC spiral bevel gear machine, machining coordinates were set up, cradle radial setting and roll ratio polynomials were proposed. With tooth contact analysis (TCA) technology, considering contact lines and transmission errors, the polynomials were taken into TCA process to study lengthwise curvature correcting rules. TCA and milling experiment showed that lengthwise curvature modification could be achieved without changing cutter diameter, contact lines and transmission error could be controlled more easily. 

Abstract:Calculation models were established based on the elastic fracture theory and complex function theory for the surface oblique crack on round tube. Change in stress intensity factors and critical crack length were investigated when surface oblique crack on round tube developing propagation considering different influencing factors. Take crack typeⅠ and typeⅡ for example, by using the strain energy density theory, a complete analysis was performed. The influence of crack initiation angle, crack angle and size on the stress intensity factors was calculated. The influence curves of crack angle on two stress intensity factors of the mixed-mode crack were obtained. Then, the influence extent was compared. Moreover, the complete analysis on the influence which cracked initiation angle, crack angle on the critical crack length was performed. The results showed that with the increase of the crack angle, the maximal and minimal values of the two stress intensity factors (KⅠ,KⅡ) were same, however, the tendency was opposite. Moreover, to typeⅠ crack , the stress intensity factors on the position of β=0 and β=2π were equal to zero.

Abstract:Dynamic performance indices of a spatial rotation 4-SPS-1-S parallel manipulator has been studied. The 4-SPS-1-S parallel manipulator has spatial three pure rotation degrees of freedom, including four SPS active legs and one passive constraining leg. Based on the velocity mapping equations of the mechanism, Jacobian matrices were built and computed. The dynamic performance indices which include load capacity performance and actuating performance were introduced and defined, and analysis equation for assessing the load capacity and actuating performance of the parallel manipulator mechanism was built. Finally a numerical example was provided for analyzing the dynamic performance indices distribution rules over the entire workspace. 

Abstract:3 A。A novel electrical discharge truing/dressing (EDD) technology which could dress non-electrical super-abrasive grinding wheels such as resin-bonded diamond wheel and vitrified CBN wheel by means of covering electrical material on the surface of wheel was proposed. The principle of removing non-electrical bond during MEDD process was illustrated. The resin-bonded diamond wheel topographies prior and after electrical discharge dressing were observed by VH-800 3-D digital microscope. The results of electrical discharge dressing under different discharge current（ie）and discharge duration（te）were compared. Experimental results indicate that the proposed EDD method is applicable to non-electrical bond wheels. In addition, discharge current has direct influence on the wheel surface topography and the performance of diamond grains. As well as, pulse duration has less influence on the wheel surface topography. The experimental results also reveal that the appropriative discharge current（ie）in dressing resin-bonded diamond wheel process is less than 3A. 

Abstract:A new high precision and fast generation algorithm of NC tool path for triangular mesh surface was proposed, which included four steps: the first, the topological structure of the triangular mesh surface was organized by improving the R*-tree spacial index structure; the second, triangular patches were obtained based on R*-tree spacial index structure and their geometric characteristics were analyzed; the third, parabola was adopted to approximate grid borders based on the first-order continuous; the fourth, the numerical control tool path was obtained through offsetting and sorting the cutter-contact points which were calculated by intersecting between the parabola and tool section. The experimental result proves that the algorithm data have strong adaptability with high precision numerical control tool path. 