Modifying the Surface of Horseshoes: Effects of Eggbar,Heartbar, Open Toe,and Wide Toe Shoes on the Phalangeal Alignment,Pressure Distribution,and the Footing Pattern

This study assesses the biomechanical effects on the phalangeal alignment, the pressure force distribution, and the footing pattern on different grounds created by different horseshoes modified in the dorsopalmar surface. Twenty-five warmblood horses were divided into five groups (n = 5). In each group, radiographic and kinetic examinations were carried out for each barefoot hoof, standard, and modified horseshoe. For radiographic measurements, a modified podoblock, simulating firm and penetrable ground, was used. For kinetic examinations, hoof and horseshoe were simultaneously equipped with sensor foils and horses were walked on different grounds (concrete, rubber, firm, and deep sand). None of the horseshoes showed an effect on the bone alignment on firm ground. On penetrable ground, the bar shoes caused a steeper palmar angle (P3), whereas with a wide toe shoe, a flatter orientation of the distal phalanx was observable. The influence on the alignment of the middle and proximal phalanx showed no constant data. On penetrable ground, pressure peaks occurred at the heels after the application of bar shoes. Moreover, pressure peaks were observable beneath the ends of the branches of the open toe shoe, and the toe and thin branches of the wide toe shoe. The footing pattern was only affected by the open toe shoe. In conclusion, the biomechanical effects of the examined modified horseshoes are mainly influenced by different ground conditions. Moreover, unintended side effects such as unexpected pressure peaks or an enhanced mediolateral sink in of the hoof occur in addition to the required impacts during a therapeutical treatment.     

柴油机GD-1系统油压控制策略仿真

基于GD-1高压共轨燃油喷射系统,对共轨油压的控制策略进行了研究和仿真。根据发动机工况分别进行开环与闭环的控制策略设计,仿真中引入控制字以在开环与闭环中进行切换,闭环控制中设计了多种控制模式,采用PID控制方法,通过试验进行在线参数整定。利用Matlab/Simulink工具对控制策略进行编程实现和初步仿真,仿真结果表明设计的控制策略能满足发动机实时运行的要求。     

一种观察甜菜胚囊的压片法

胚囊观察是植物胚胎学的主要研究方法之一。我们在学习了酶解法之后,摸索研究了一种观察甜菜胚囊的压片法。其步骤:固定、硼砂洋红整体染色、酸解离、剥离胚珠、透明、压片、观察。观察到了胚囊的一些情况。此法简捷易行,成本低。     

Effect of domestic processing and cooking methods on phytic acid and polyphenol contents of pea cultivars (Pisum sativum)

All the pea varieties differed significantly (p<0.05) in their phytic acid content. The field pea cultivars had significantly (p<0.05) higher levels of phytic acid and polyphenols than those of vegetable pea varieties. All the domestic processing and cooking methods could reduce the contents of phytic acid and polyphenols but germination for 48 hours seemed to have a marked lowering effect on the levels of these antinutrients in peas.     

微灌田间管网支毛管优化设计探讨

本文以单位面积管网造价最小为目标，导出了平地田间管网优化设计模型及支毛管压力差分配比例，可供微灌管网设计及灌水单元划分和支毛管布置等参考。     

增压柴油机进、排气管压力波动计算与分析

分析了影响进气管波动效应、增压柴油机排气管压力波动和废气能量利用的因素，通过对缸内工作过程的计算，编制了增压柴油机进、排气管内气体压力波动计算程序，利用该程序对增压柴油机的进、排气管内气体压力波动过程进行了计算。分析了4102BZLQ柴油机在额定转速下，不同的进、排气管长度对进、排气管内气体流动状态的影响，并提出改进意见。     

应变式压力传感器在离散介质中应用的误差分析

分析了膜片应变式压力传感器测量离散介质压力时产生误差的原因，用试验的方法建立了测量误差与介质分布密度间的相关关系。对传感器的非线性度及温，湿度引起的测量误差亦进行了分析。     

气波增压柴油机进气管设计与优化

以SOFIM 2．5L涡轮增压中冷柴油机为样机，设计了气波增压柴油机进气管。用正交设计优化试验进气管的结构组合，并用三维设计软件UG进行几何建模及结构分析，找出质量最小、内腔容积最大的进气管，再用ANSYS软件对其进行流动分析，找出平均进气质量流量最大的进气管；综合结构优化和流动优化结果，确定最终的气波增压柴油机进气管，采用快速成型技术制成其模型并在气道试验台上与原管进行稳态流动对比试验。试验结果表明，该管比原管进气质量流量平均提高近7％，基本可满足气波增压柴油机的要求。     

重力给水输水管路优化设计

在分析影响重力输水管渠设计的主要因素基础上，以输水管渠系统投资最小为目标函数，建立了优化设计的数学模型。并推导出计算公式，应用这一公式，确定地压管渠与有压管道最优长度和有压管道最优管径。     

旋转失速条件下离心泵叶轮压力脉动特性研究

离心泵发生旋转失速时,失速团周期性地生成和脱落往往会诱发低频压力脉动,严重影响水泵的安全稳定运行。为研究离心泵旋转失速对压力脉动的影响,采用动态混合非线性SGS模型对一离心泵叶轮进行了大涡模拟,得到了叶轮内部流场和叶片上的压力脉动特性。对不同旋转时刻的内部流动进行分析,可以看到旋转失速团产生于叶片吸力面头部附近,沿圆周方向向叶片压力面运动,并逐渐衰减。对叶片上的压力脉动进行分析,发现当旋转失速发生以后,叶片上的压力脉动幅值远大于非失速工况。失速团对叶轮中的压力脉动有很大影响,叶片上的压力脉动频率以失速频率为主;叶片吸力面头部压力脉动幅值最大,并沿着水流方向,叶片上的压力脉动幅值依次减小。随着流量进一步减小,叶轮进入深失速工况,压力脉动主频幅值有所降低,而失速频率逐渐增大。