泵站正向进水前池扩散角对池内流场结构的影响

针对从多沙河流取水的大型泵站进水前池内水流流态较差,易在池内产生大尺度回流区域,导致泥沙严重淤积等问题,该研究以甘肃省景泰川电力提灌工程典型泵站的正向进水前池为研究对象,构建不同扩散角体型结构的正向进水前池三维模型,基于Mixture多相流模型和Realizable k-ε模型开展数值模拟计算,阐明了正向进水前池流场结构特征,提出了有效改善正向进水前池流场结构的扩散角范围。结果表明：泵站机组全开时,正向进水前池内流场结构对称分布,在进水前池中央形成主流区,两侧形成回流区,中央主流区域水流流速远大于两侧回流区,主流效应显著;随着扩散角的减小,两侧低流速区面积减小,主流区域流速呈下降的趋势,区域宽度呈现增加的趋势,进入前池的水流扩散效应增加明显;扩散角在25°～30°之间时,入池的水流沿流程发展和扩散较为充分,有效改善多泥沙河流引水泵站前池的泥沙淤积,研究成果可为同类泵站的设计和更新改造提供指导和参考。     

青枣划痕器喂入性能及其结构参数的分析

本文对几种不同结构的划痕器刀架从自锁条件到最佳传动角方面作了一些分析,得出了刀架结构参数的取值范围及理论计算公式。为通道式仿形划痕机喂入性能的设计提供了理论依据。     

苗圃常用除草剂草甘膦对胶东卫矛生理生化影响的研究

主要研究草甘膦对胶东卫矛生长发育的影响。实验通过对88.8%草甘膦水溶性粒剂在三种浓度处理下对胶东卫矛叶片内叶绿素含量、POD活性、SOD活性、质膜相对透性的测定,再结合生长量指标进行分析。结果表明:草甘膦即使浓度在1.5 g/L时,仍会对胶东卫矛苗木的生长量产生极强的抑制作用。所以在胶东卫矛苗圃地除草时,应避免接触到苗木的茎叶。     

Effect of Training on Body Angle in 1 km Trotter of Yili Horse

This experiment aimed to analyze the effects of different training stages on the limb angle of the Yili horse in 1 km trotter.8 Two-year-old Yili horses were selected as the test subjects.Through the 1 km trotter training for three months,the trotter test race was organized before and after the training.The video analysis was used to analyze the maximum limb opening angle,the minimum contraction angle and the extreme difference of limb angle of straight and curved horses in the process of exercise,and the difference of limb angle changes in different training stages were analyzed.The results showed that in the straight movement,the maximum opening angle and minimum contraction angle of shoulder angle before training were significantly less than those after three months training (P<0.05).The maximum opening angle and angle range of the elbow and the back fetlock angle before training were extremely significantly smaller than those after the three months training (P<0.01).The carpus and tarsus angle of the minimum contraction angle and angle range were extremely significantly different from those after the three months training (P<0.01).The maximum opening angle,minimum contraction angle and angular range of the front fetlock angle before the training were extremely significantly different from those after the three months training (P<0.01).In the curve movement,the maximum opening angle of the shoulder angle was significantly greater than those before the three months training (P<0.05).The minimum contraction angle and angle range of the elbow angle and the front fetlock angle were significantly different from those before the three months training (P<0.05).The minimum contraction angle of the carpus angle was extremely significantly greater than that of the three months after training (P<0.01),the angle range of the carpus angle before the training was significantly greater than three months after training (P<0.05).The maximum opening angle and angle range of the carpus angle were significantly greater than those before the three months training (P<0.01).The minimum contraction angle of the stifle angle before training was extremely significantly less than that after training for three months (P<0.01),the maximum opening angle and the angle range of the tarsus angle was significant greater than those before the three months training (P<0.05).In summary,the training affects the change of limb angles during the movement of the horse,and improves the stability of the horse movement and reduces the risk of injury.     

基于方位角夹角的三岔路口道路中线优化算法

基于约束Delaunay三角网法是从已有面状道路图层数据中自动获取道路中线的常用算法.根据此算法得到的岔路口处的道路中线需要进一步优化处理,三岔路口道路中线的优化处理为其中问题之一.提出了方位角夹角的概念和基于方位角夹角三岔路口道路中线的优化处理算法,根据三岔路口三条道路中线的方位角夹角的大小,求取岔路口中线交点,实现三岔路口的道路中线的优化处理.     

斜角切削的理论分析

就刀具λ_s≠0°时刀具的标注角度、实际工作角度进行了理论分析，推导了λ_s影响下的工作角度计算公式，并给出了λ_s对刀具工作角度的影响曲线。     

美洲黑杨新无性系木材细胞次生壁S_2层微纤丝角株内变异的初步研究

对６年生美洲黑杨无性系３６６、３７０，Ｉ—６９的Ｓ２层微纤丝角（ＭＦＡ）进行了研究。ＭＦＡ在不同无性系间，同一年轮的不同高度之间存在显著差异；而胸高部位径向变异不显著。同一年轮的ＭＦＡ随高度增加而降低；在径向，ＭＦＡ有从髓心向外逐渐减小的趋势。从无性系平均看，三无性系ＭＦＡ的大小次序为３６６＜３７０＜Ｉ—６９。     

深栽造林钻孔机研制——钻尖结构参数与切刀刃角对钻孔阻力矩的影响

1995年以来,通过对3种形式深栽造林钻孔机的研制和不断改进,一种钻孔效率较高、操纵简单、移动方便的牵引式设备得到了认可.在设备研制成功的基础上,对钻孔机钻头不同钻尖、不同切土刀刃角进行了实地试验研究和分析. 结果表明,钻尖的类型对钻孔阻力矩有一定的影响,但较小;切土刀刃角在30°,45°,60°的变化,对钻孔阻力矩几乎没有影响. 由此而推论,影响深孔钻的钻孔阻力矩的主要因素是升土阻力.     

氮肥对油菜分枝生产力的调节作用

研究不向氮肥用量对杂交油菜“秦油２号”主序及各枝序分枝生产力的影响。结果表明：（１）随着氮肥用量增加，主序产量占单株产量的比例逐渐降低，施氮量过大则又略有回升．主序籽粒约占产量的１／４时，单株产量最高．（２）在不同氮肥用量下，上部分枝生产力的变化趋势类似于主序，而中部分枝则与全株一致。（３）在分枝产量构成因素中，氮肥对分枝角果数的影响最大。（４）主序及上位分枝中氮素的累积量受氮肥用量的影响程度较小，而中下位分枝则较大．     

点基形四面体的确定参数及作图

Ｅ．Ａ．格拉祖诺夫和Ｈ．Φ切特维鲁新著的《轴测投影学》中提及“根据波克－许华尔兹定理,要想按点基形四面体原形的投影来重新定出其原形,只要已知其形状,形状可由五个参数的条件来决定．”［１］本文对确定参数和作图,作进一步的研究和探讨。