垄台修复中耕施肥机关键部件的改进与试验

针对东北垄作区原垄免耕播种后,垄形破坏,玉米出苗后需进行垄台修复施肥,但作业过程中存在机具堵塞严重,行间玉米秸秆被机具挑起伤苗,以及机具作业过程中动力消耗大等问题,设计改进了垄台修复中耕施肥机的关键部件,优化了关键参数.田间试验表明:平板直刀型破茬松土方式动力消耗小、防堵效果好,采用的凹面双圆盘进行垄形修复,起土效果好,能够有效防堵.     

新疆机械采棉技术发展的系统分析与思考

机械采棉技术是一项涉及诸多学科的系统工程.为此,从棉花生产、轧花加工和纺纱生产这一棉花产业链的角度出发,对新疆发展机采棉的机遇和优势、威胁和挑战进行了系统分析.其中,对新疆手摘棉、机采棉和进口美棉的质量进行了对比分析.最后,提出发展机采棉必须将长期目标与短期目标结合起来,在稳步发展的前提下,提高质量,优化工艺,以实现较高的综合经济效益.     

基于模糊物元方法的温室采暖模式评价

针对目前温室采暖综合环境调控存在的问题,建立了温室采暖模式评价指标体系,提出了基于模糊物元理论方法的温室采暖模式选择的综合评价方法,介绍了该方法的原理.以哈尔滨市香坊农场为例,进行了实证评价分析,将模糊物元方法分析结果与灰色关联投影法和投影寻踪方法的分析结果进行了对比分析,所得结果方案排序基本一致,且与实际情况相符.这说明,该方法用于温室采暖模式选择是行之有效的,可以用于我国日光温室采暖模式选择的定量分析.     

根茎类中药材收获装备现状及其收获工艺

种植中药材现已成为我国农村农民增加收入的重要途径之一,但目前在中药材的收获上尚存在收获效率低和劳动强度大等一系列问题.为此,通过对国内外根茎类中药材收获装备现状的研究,分析了影响根茎中药材收获的主要问题,提出了全新的深根中药收获工艺,其设计思想为根茎类中药材收获装备的设计开发提供了新的思路.     

提高特殊柱塞泵往复密封寿命的优化设计

针对输送含颗粒介质柱塞泵的柱塞、填料寿命问题,从接触型往复密封的摩擦学机理出发,通过优化匹配柱塞直径、行程及泵速各参数,合理控制柱塞的线速度,降低摩擦速度,对柱塞填料密封进行优化设计;通过求解间隙中的流体力学层流运动问题,合理控制冲洗液的压力,保证全压密封系统中接触区的液膜处在混合润滑状态下工作,使密封副有良好的润滑;提出了两种填料函方案,并和采用不同表面处理工艺的柱塞及多种填料搭配组合进行试验.试验结果表明,密封累计运行了4 455 h后,组合1和组合2柱塞的磨损仅为0.03 mm和0.05 mm;在生产实际中,改进后的密封设计,使柱塞及填料的使用寿命从原来的1 500 h提高到4 500 h以上.     

基于FLUENT的单-双涡室离心泵径向力分析

以某电厂3715L型脱硫泵为模型,应用商业软件FLUENT,采用标准k-ε湍流模型和SIMPLEC算法,对单-双涡室离心泵内部流场进行模拟,分析了这两种泵静压力和速度场的分布规律,并对径向力进行了计算分析.通过对比分析发现,单涡室离心泵在非设计工况点时隔舌两侧区域出现较大压差,作用于叶轮产生径向力,小流量时叶轮出口出现不对称的高速流体;双涡室结构能够有效地改善非设计工况点时压水室能量的转化,小流量时叶轮出口的高速液体呈对称分布,从而降低了压水室压差,起到了平衡径向力的作用;通过计算发现,偏离工况点时双涡室结构设计能有效地减小径向力.数值模拟的结果与现有理论的基本吻合,实际运行情况稳定,可以为更好地认识和设计双涡室离心泵提供依据.     

添加剂湍流减阻流动的传热特性数值计算

采用雷诺应力模型和Cross粘度方程,对二维轴对称圆管内湍流流动的聚丙烯酰胺稀溶液（PAM）的流场和温度场进行了数值模拟.在数值计算结果的基础上,系统研究了流速对减阻流体的减阻性能和传热特性的影响.结果表明,减阻流体的减阻率和传热降低率随流速的增大逐渐增大到渐进值,而且传热降低率恒大于减阻率.减阻流体柯尔本（Colburn）因子与摩擦系数的对比结果表明柯尔本比拟,特别是在较低流动雷诺数下有较大偏差.     

田间土壤力学参数测定方法研究

总结了车辆地面力学研究常用的土壤力学参数检测方法,结合现代农业车辆智能化发展思想,提出了结合车辆动力学参数的在线检测进行土壤力学参数估计的方法。     

海参微波冻干过程活性成分保存研究

针对海参传统干制技术周期长、复水困难、活性成分损失率大的问题,寻找一种合理的干制海参方法以有效保存海参中的活性成分,同时操作成本又较低.研究了不同干燥工艺对海参活性成分的影响规律,以及各种干燥方式的能耗和复水性,得出微波冷冻干燥可有效保存海参活性成分,其能耗较低,干燥周期较短.最后得出合理的微波冷冻干燥工艺参数:最佳物料表面温度上限设为60℃,最佳功率取2 W/g.能耗比常规冷冻干燥节约近50%.     

Effects of Dietary Binders on Survival and Growth Performance of Postlarval Tongue Sole, Cynoglossus semilaevis (Günther)

A 30‐d feeding experiment was conducted in tanks to investigate the effects of four different binders (2% in microdiet) on the survival, growth performance, and specific activity of digestive enzymes in tongue sole, Cynoglossus semilaevis Günther, postlarvae (24 d after hatching, with initial average wet weight of 22.4 ± 6.65 mg [mean ± SD]). Five approximately isonitrogenous and isoenergetic microbound diets were formulated with carrageenan (Car), sodium carboxymethylcellulose (CMS), sodium alginate (SA), and gelatin (Gel) as binders, and a diet with no special binder as a control. A commercial diet (RQ Com., manufactured by Marubeni Nisshin Feed Co., Ltd., Chita, Japan) was used as another tested diet, and Artemia nauplii was used as live prey control. The results showed that the survival of the fish fed SA diet (31.3%) was significantly higher than that of fish fed CMS (21.8%), Car (10.8%), and control (21.8%) diets (P < 0.05), but significantly lower than that of the fish fed the live prey (54.5%) diet (P < 0.05). The results of growth followed the similar pattern as that of survival, although there were no significant differences in specific growth rate (SGR) among fish fed SA, CMS, Gel, the control, and RQ diets (7.2, 6.8, 7.0, 6.9, and 7.3% per day; P > 0.05). However, fish fed Car diet had a significantly lower SGR (5.9% per day) than fish fed other diets. Percentages of secreted amylase in fish fed artificial diets were not significantly different, but fish fed artificial diets had significantly higher (P < 0.05) secreted amylase than live prey group. Percentage of secreted trypsin in fish fed SA diet (54.9%) was relatively higher compared with other binders, and not significantly different from RQ Com. and live prey treatments. However, trypsin in fish fed Car diets (29.3%) was significantly lower than in other groups. Specific activities of alkaline phosphatase (AP) in the intestine and AP and leucine aminopeptidase N in brush border membranes in fish fed SA diet (264.6, 1882.8, and 187.2 mU/mg protein) were relatively higher compared with other binders. These results indicate that SA is one of suitable binders compared with carrageenan, CMS, and gelatin in microdiet of postlarval tongue sole.