径向柱塞泵配流轴双三角槽结构分析

在新型径向柱塞泵的设计中,要想把原来常规设计的排量规格为63ml/r的液压泵在壳体尺寸、配流轴外径以及主轴外径不变的情况下,使其排量增加一倍以上时,气穴现象和液压冲击现象比较突出.在配流轴上加工双三角槽使密封容腔以合理的过渡过程提前与吸油通道和排油通道连通是解决问题的方法之一.本文讨论双三角槽的结构和过渡过程情况,分析它的可行性,讨论结果认为这是一种较好的方法,这种设计思想对其它型式液压泵的改进设计有一定的指导意义.     

活塞式氧压机一级气缸进气压力作提高改造与动力分析

通过热力学计算，提出了氧压机一级气缸进气压力作提高改造的原则、方案及改造意义。对改造后压缩机的承载及机器运行稳定性进行了分析，为氧压机的改造提供了理论依据。     

直径950 mm轧机推拉床推杆断裂失效分析

某厂直径 95 0mm轧机推拉床推杆使用一个半月后发生断裂 .本文通过对其化学成分分析、力学性能测定及微观检验分析 ,获取了推杆断裂的失效原因 ,主要是其内在质量不良引起的早期失效所致     

多灯泵浦椭圆腔棒状放大器的效率设计

通过细致的数值计算和理论分析，系统在阐述了在放大介质和泵浦灯口径一定的情况下，光腔膜层反射率，泵浦灯数，椭圆结构参数，水管结构参数对泵浦效率的影响，并着重分析了当激活介质离开椭圆焦点靠近泵浦灯时放大器泵浦效率的变化。这结果对多灯泵浦椭圆腔棒状放大器设计有重要参考价值。     

活塞动态上止点的微接触直接测量法

介绍活塞动态上止点的微接触直接测量法，该测量法具有上止点定位精度高、不需热力损失角修正、且不损坏压力传感器等特点．     

Feasible Command Strategies for the Control of Motion of a Simple Mobile Robot

An error in the model of the disk-rod system of Ref. 1 is corrected.     

Silicone rod extraction of pharmaceuticals from water

Silicone elastomer (in the form of a flexible rod) is one of the materials currently tested for use in analytical extraction techniques and passive sampling devices. We investigated the applicability of this material for the enrichment of selected polar pharmaceuticals (antipyrine, carbamazepine, diclofenac, ibuprofen, bezafibrate) from water. Time-resolved batch extraction tests (up to five weeks in duration) were performed in stirred water samples ( approximately 0.5 L) with 2-cm-long silicone rod pieces. After re-extraction of trapped compounds with methanol, analysis was performed using liquid chromatography coupled with mass spectrometry. Distribution equilibrium was reached after a test duration of seven days. The silicone rod/water partition coefficients of the investigated pharmaceuticals range from 4 (antipyrine) to 1250 (diclofenac), and are related to the hydrophobicity of the compound. Enrichment of these pharmaceuticals in the silicone rod is lower than for other compound classes (chlorinated and polycyclic hydrocarbons).     

The Slip Velocity at the Edge of a Porous Medium: Effects of Interior Resistance and Interface Curvature

Singularity methods are used to analyze creeping planar flow in the annulus between concentric cylinders, when a portion of the annulus is filled with an array of regularly spaced rods adjacent to the inner cylinder. The rods are evenly spaced on concentric circles, and the circles are spaced such that the array resembles a square lattice bent into a circle. The rods and inner cylinder are stationary, and steady rotation of the outer cylinder generates the flow. The quantity of interest is the slip velocity, the mean velocity at the interface between the array and the unfilled portion of the annulus. The primary part of the study concerns the influence of the interior rods on the interfacial velocity, and to this end the velocity is found as successive circles of rods are removed, starting with the circle closest to the inner cylinder. The calculations are carried out for solid volume fractions from 0.0001 to 0.1, and these show that the slip velocity is virtually unchanged as the interior circles of rods are removed, until only one circle remains and then the velocity is of order 10% larger than that for the full array. Hence the velocity at the edge of a sparse porous medium depends minimally on the hydrodynamic resistance of the obstacles in the interior. In the secondary part of the study, it is found that curvature of the interface does not influence the velocity there.     

PERTURBATION ANALYSIS FOR WAVE EQUATION OF NONLINEAR ELASTIC ROD

The longitudinal oscillation of a nonlinear elastic rod with lateral inertia was studied. Based on the far field and simple wave theory, a nonlinear Schrodinger (NLS) equation was established under the assumption of small amplitude and long wavelength. It is found that there are NLS envelop solitons in this system. Finally the soliton solution of the NLS equation was presented.     

Vibration of rods with a concentrated mass in the presence of non-conservative forces

Summary Separable and non-selfadjoint boundary-value problems representing the vibration of linearly elastic unidimensional systems are considered. The elastic system is modelled as a continuous distributed-parameter system where singularities in the mass distribution function can be neatly taken into account. Specifically, extending Green's function approach, the free vibration, stability and forced vibration of fixed-free rods with a tip mass and under the action of uniformly distributed non-conservative loads have been investigated analytically.Support of this research through the NSERC Grant No. OGPIN013 is greatly appreciated