稀燃汽油机瞬态空燃比的滑模-神经网络控制     

王莉  刘德新  李万众 《农业机械学报》2007,38(10):1-4

提出了稀燃汽油机空燃比滑模-神经网络控制方案,采用滑模变结构控制对稀燃工况的空燃比进行反馈控制,采用神经网络实现对进气量的精确预测和油膜动态特性的前馈补偿,进而实现对稀燃发动机瞬态空燃比的精确控制。采用自行开发的电控系统,在一台稀燃发动机上进行了瞬态空燃比实验。实验结果表明:节气门急速变化时空燃比超调可以控制在1个空燃比单位以内,调整时间不超过3s;转速越低,节气门变化越剧烈;空燃比超调越大,调整时间越长。  相似文献   

应用GOMPERTZ模型预测交通生成量     

李海涛  曹成海 《农业装备与车辆工程》2007,(4):39-40

应用GOMPERTZ模型预测了出行强度，并通过实际数据对GOMPERTZ模型参数进行了标定，采用实例对模型进行了比较分析。结果证明了GOMPERTZ模型用于小区居民出行强度预测的可行性，以及具有一定的优越性。再根据小区预测年的的人口便可以得到小区的交通生成量。  相似文献   

适期收割对稻谷损失影响的研究   总被引：5，自引：3，他引：5  

徐润琪  刘建伟  张萃明  後藤清和  三轮精博 《粮食储藏》2003,32(3):47-50

稻米原粮爆腰率是影响加工过程中出米率的重要因素。经调查，农家交售原粮中爆腰率高达25％，其中有干燥、储藏方面的原因，也有收割期不当的原因。本研究从一株稻穗中谷粒含水率与爆腰率的关系分析着手，通过对田间不同品种、不同含水率稻谷爆腰率的测定，并用概率统计方法进行分析的结果证明，完整谷粒的平均含水率在20％以上时收割，可以有效地避免田间爆腰率的发生。  相似文献   

GA3和PP333对萝卜生长及产量的影响     

应冬勤  陈旦蕊  苏士法  郑春明 《中国农学通报》2007,23(6):363-363

通过研究不同浓度的GA3和PP333及两激素不同浓度的互作对萝卜叶面积、叶重量、叶子叶绿素含量及根冠比的影响。结果表明，两者对叶子叶绿素含量没明显影响，但GA3在促进叶子的生长，叶面积的增大上以10~30ppm效果最好，而PP333虽然能抑制叶子的生长，但在肉质根生长中后期试用50ppm浓度的PP333，抑制了叶子的生长，反而促进了光合产物输送到肉质根，起到增产的作用。适当浓度的GA3和PP333及两者结合增产效果明显  相似文献   

Human Simulated Intelligence Motion Control for Three-link Acrobot on Horizontal Bar     

ZHANG Hu  LI Zu-shu  GU Jian-gong  CHEN Gui-qiang  TAN Zhi 《保鲜与加工》2007,(3):74-78

The design of multi-controller and multi-mode control law is presented for the three-link Acrobot on horizontal bar by employing Human simulated intelligent control method based on sensory-motor Schema.Imitated the characteristics of gymnast's swing-up and handstand movement,the control process of robot is divided by six sequence phase.Then the sensory cell and motor cell and the group of sensory-motor schema is designed based on the analysis of quality-quantity combination.The simulation results show that the controller ensures the gesture and the energy to the desired goal,farther more the motion control of giant swing backword is realized in the simulation.  相似文献   

Comparative Experiment Research on Seismic Behavior of New Reinforcement Scheme Coupling Beam with Slab     

PI Tian-xiang  LIU Guang-wei  FU Jian-ping  BAI Shao-liang 《保鲜与加工》2007,(8):107-113127

  相似文献   

Minimal Periodic Solutions of SuperquadraticFirst Order Convex Hamiltonian Systems     

Zhang Shiqing 《保鲜与加工》1996,(6):96-103

This paper generalizes all known results on Rabinowitz's minimal periodic solution conjecture under the assumption that Hamiltonian function is C2 strictly convex.  相似文献   

Analysis of Load-bearing Characteristics of Concrete Pile Composite Foundation     

HU Zhi~  WANG Xian-neng~  HU Dai-wen~  DAI Jun~ 《保鲜与加工》2004,(3):46-50

Some conclusions were drawn from two groups of in-site tests on concrete pile composite foundations. In the tests, it was found that the pressure under the rigid loading slab is different, in which the pressure under the center of the slab is the less and under the edge of the slab is the biggest. The pile-soil stress ratio is not a constant; it increases with the adding of the load. Most of the pile-soil ratio vary from 9 to 13 in these tests and the load that the piles share can be more than seventy percent of the whole load. It was proved that the bearing capacity of the concrete pile composite foundation is high with a little settlement, so it will be used more and more in the future.  相似文献   

Prediction of the Economic Development for the Circumjacent Reservoir Region of the Longtan Hydropower Project Using Grey Quantitative Analog     

Duan Yurong Zhu Jinming Liu Size Hong Guiyu 《保鲜与加工》1996,(5):95-99

In order to overcome some technical difficulties,we adopt ingenously the grey models combined with the quantitative analog method,and select the Dan Jiangkou Project which has accumulated practical operation data for a long time as the analog project to predict the economic influence for the circumjacent reservoir region of the Longtan hydropower project.On the basis of analog we have built various industrial economic grey models,and compare them with the corresponding predictions for the unconstructed reservoir case.The predictions of the former are greatly larger than the later ones.and hence provides a certain scientific basis for the central leaders to make a decision for constructing the huge hydropower project ultimateiy.  相似文献   

Deformation of deep foundation pits due to excavation and dewatering considering the change of void ratio and permeability coefficient with current stress of soil     

Shao Yu  Jiang Jie  Ma Shaokun  Lyu Hai-bo  He Jianxing  Chen Junyu 《保鲜与加工》2015,(2):92-100

基于修正剑桥模型理论,推导了孔隙比e随土体当前应力变化的方程,同时比选了4组经典的描述渗透系数k随孔隙比变化的方程,选择了其中一组最佳的估算公式,编写ABAQUS用户子程序VOIDRI和USDFLD,以实现孔隙比和渗透系数随土体当前应力的变化。在此基础上,研究深基坑降水开挖所致的坑内外土体的变形、围护结构的变形及弯矩,得到以下结论：当考虑孔隙比随土体当前应力变化时,坑外地表沉降量、墙体的水平位移、地下连续墙的弯矩、坑底隆起量均大于孔隙比为定值时的情况;当考虑渗透系数随土体当前应力变化时,坑外地表沉降量、墙体的水平位移、地下连续墙的弯矩均小于渗透系数为定值时的情况,但同时考虑渗透系数和孔隙比变化情况时,其对坑底的隆起量的影响可以忽略不计。  相似文献