青饲料收获机自动磨刀装置及弧形弯刀设计

设计了一种青饲料收获机的自动磨刀装置，主要由主机架、磨刀、磨刀驱动装置、护罩及拆卸装置组成。在此基础上设计了一种弧形弯刀作为滚筒动刀，这种弧形弯刀更利于磨刀装置的磨刀工作、提高饲料切割的工作效率。此装置进一步提升了国产青饲料收获机的行业核心竞争力。      

Beam pumping process modeling and parameters optimization based on generalized regression neural networks for energy conservation

This paper presents a data-mining-based beam pumping unit process modeling and parameters optimization method to solve the problem of inefficiency and energy-intensive of beam pumping unit. The ideality of process parameters is one of the main factors influencing system efficiency and energy consumption, while the effectiveness of mode plays a key role in process parameters choosing. Beam pumping unit system is a complicated nonlinear system, and is hardly to be precisely described by precise mathematical models. Generalized regression neural network (GRNN), which is powerful in nonlinear mapping and generalization, is suitable for nonlinear systems. Therefore, GRNN is proposed to model the beam pumping unit in this paper, and the experimental results show that the fitness is good. Then the trained model is applied to optimize the decision parameters by vector evaluated particle swarm optimization based on Pareto (VEPSO-BP), and at last the resulting parameters are applied to the production. Experimental results show that after using the optimal parameters, the efficiencies and energy consumptions increase more than 6.6% and decrease more than 4.1% respectively, which illustrates the feasibility and effectiveness of the proposed method.     

“S”形刃球头立铣刀的研究（Ⅰ）──数学模型

在分析球头立铣刀刃磨方法的基础上,建立了“Ｓ”形刃球头立铣刀前、后刀面以及切削刃的数学模型．模型的建立对“Ｓ”形刃球头立铣刀几何参数的分析及优化、切削机理的研究、刃磨参数的选择以及刃磨装置的设计都将具有理论意义;对加快“Ｓ”形刃球头立铣刀的国产化制造具有实用价值．     

高地下水位冻土区抛物线形渠道冻胀力学分析

考虑渠道断面各截面地下水位以及局部几何特性逐点不同的特殊性并结合Winkler假设,提出了高地下水位冻土区抛物线形渠道衬砌法向冻胀力与切向冻结力计算方法及截面内力计算公式.考虑曲梁曲率影响提出基于曲梁理论的截面正应力计算方法及抗裂验算公式.以河北某抛物线形渠道为例,分析衬砌截面轴力、弯矩及应力分布规律.结果表明:轴力自渠顶向渠底中部逐渐增大且均为压力;衬砌板主要在负弯矩作用下凸向内侧,仅在临近渠底时由负变正转而凸向外侧;由于存在拱效应,各截面均以压应力为主,仅渠坡中下部内侧及渠底中部附近外侧出现拉应力从而易导致开裂.分别应用直梁理论和曲梁理论计算衬砌板截面应力并进行对比分析.发现渠底中心附近曲率较大处两者相对误差可达11.78%,且直梁理论的计算结果量值偏小、安全性低,应当基于曲梁理论进行应力分析更加合理.     

横向正应变对梁接触问题的影响

应用深梁理论，分析了受均布荷载悬臂梁与刚性地基接触的全过程。消队 了接触区间端占的集中反力，其接触区间明显大于只考虑剪切变形的梁理论的结果，揭示了横正应对梁的接触问题有着不可忽略的影响。     

金属/防锈油防锈性能试验——多电极探头直测法

提出了金属/防锈油防锈性能试验——多电极探头直测法.该方法测评速度快，比ISO湿热、盐雾法缩短试验时间几十到几百倍.设备体积小，便于携带，特别有利于缩短新产品研制周期、在线检测和节能.     

协拨组合式玉米条带秸秆清理装置设计与试验

针对现有条带秸秆清理装置集行效果差、秸秆清理率低等问题，提出了一种协拨组合式条带秸秆清理方案，从力学角度对比分析不同齿形清秸轮拨送秸秆的过程，设计了一种径向锐化协拨清秸轮，清秸轮半径为162.5 mm、齿数为12、齿长为65 mm。开展了协拨组合式条带秸秆清理装置的仿真试验，以径向锐化清秸轮的工作参数为影响因素，秸秆清理率为指标，开展离散元仿真试验，分析了清秸轮工作过程中秸秆运动、土壤扰动及秸秆清理率的变化。结果表明，试验因素对秸秆清理率的影响由大到小为侧倾角、前进速度、前倾角，当机具前进速度为7.8 km/h、清秸轮前倾角为31.7°、侧倾角为13.4°时，秸秆清理率最高为91.62%。开展了协拨组合式条带秸秆清理装置和整机的作业性能田间试验，结果表明协拨组合式条带秸秆清理装置工作稳定，秸秆清理率为87%～90%,实现了条带秸秆清理装置的设计目标。     

Effects of electron-beam irradiation on blueberries inoculated with Escherichia coli and their nutritional quality and shelf life

Fresh blueberries have become a popular new functional food because of their remarkably high levels of antioxidant phytonutrients and health benefits. However, the potential prevalence of human pathogens on blueberries has become an increased concern because they are consumed fresh. Procedures effective in decontamination and extending shelf life without affecting fruit quality are needed. Electron-beam irradiation was applied to fresh blueberries at the doses ranging from 0.5 to 3.0 kGy and its effectiveness for inactivating Escherichia coli (E. coli) K-12 and extending shelf life were investigated. The decimal reduction dose, D₁₀ values, of E. coli in cultural medium and blueberries were 0.43 ± 0.01 kGy and 0.37 ± 0.015 kGy, respectively. Irradiation reduced bacteria inoculated on blueberries from 7.7 × 10⁸ CFU/g to 6 CFU/g at 3.13 kGy and decreased the decaying of blueberries stored at 4 °C up to 72% and at room temperature up to 70% at this dose. No significant effect on the total monomeric anthocyanins, antioxidant activity, and l-ascorbic acid content of blueberries was observed from irradiation at doses ≤3 kGy. However, significant decreases in the antioxidant activity and l-ascorbic acid content were found in both control and irradiated blueberries after storage at 4 °C for 7 and 15 d. Information obtained in this study indicates that low dose electron-beam irradiation is effective in reducing E. coli and extending shelf life while maintaining the antioxidant properties of blueberries.     

钢筋锈蚀对混凝土梁破坏模式影响的试验研究

研究钢筋锈蚀对混凝土梁破坏模式的影响.对4组共21根不同剪跨比、不同锈蚀程度的混凝土梁进行了试验，研究发现，纵向配筋率及剪跨比相同的情况下，随着纵筋、箍筋锈蚀程度的变化，梁会产生弯曲、剪压、剪切-粘结3种不同形态的破坏.针对此现象，基于试验研究结果并结合相关文献的试验结果，根据现行规范中的分析理念建立了考虑剪跨比、箍筋锈蚀率、纵筋锈蚀率及粘结退化等因素影响的锈蚀混凝土梁受剪承载力计算公式.据此再考虑弯剪区的平衡条件，分析讨论得出了试验梁产生破坏形态转变的临界条件和锈蚀混凝土梁构件的综合承载能力的变化规律，从而建立了锈蚀混凝土梁破坏模式转变的分析模型.据此模型分别以纵筋锈蚀率和箍筋锈蚀率为横、纵轴，考虑剪跨比等因素得出临界曲线划分的破坏形态区域与试验结果吻合较好.