双端曲面齿轮式柱塞泵运动特性分析与实验

为解决斜盘式柱塞泵摩擦副的磨损问题,提出了一种新型轴向柱塞泵,用双端曲面齿轮代替了斜盘,用齿轮副代替了摩擦副。利用端曲面齿轮副传动原理建立了单柱塞、六柱塞双端曲面齿轮式柱塞泵的运动特性数学模型,得出了柱塞运动规律。通过ADAMS虚拟样机建立了柱塞泵运动特性仿真模型,验证了新型柱塞泵柱塞运动的可行性。利用LH-050型激光位移传感器对柱塞泵运动特性测试实验台进行了相关测试,通过实验测试结果和理论值对比发现:实验数据与理论计算值吻合较好,误差控制在5%以内,证明了柱塞泵运动特性理论模型的正确性。     

基于Proteus的同步器倾斜性检测系统设计

为了满足同步器总成检测要求,文章设计了一套基于同步器齿毂齿套倾斜性检测系统。文章不仅完成同步器倾斜性检测系统机械结构、硬件、软件的设计,还介绍了所研制的计算机和单片机控制的汽车同步器总成倾斜量检测系统、检测原理及试验仿真。此外,还提出基于Proteus的系统开发方法,应用Proteus进行原理图设计,根据Proteus中的电子元件特性模拟了检测系统的微位移传感器,并利用Proteus与Keil的联合调试进行仿真分析,得出仿真数据。相比于其他检测装置,该系统在检测精度和自动化方面更臻完美。     

Increasing patient safety in veterinary transfusion medicine: an overview of pretransfusion testing

Objectives – To review the principles and available technology for pretransfusion testing in veterinary medicine and discuss the indications and importance of test performance before RBC transfusion.
Data Sources – Current human and veterinary medical literature: original research articles and scientific reviews.
Summary – Indications for RBC transfusion in veterinary medicine include severe anemia or tissue hypoxia resulting from blood loss, decreased erythrocyte production, and hemolyzing conditions such as immune-mediated anemia and neonatal isoerythrolysis. Proper blood sample collection, handling, and identification are imperative for high-quality pretransfusion testing. Point-of-care blood typing methods including both typing cards and rapid gel agglutination are readily available for some species. Following blood typing, crossmatching is performed on one or more donor units of appropriate blood type. As an alternative to technically demanding tube crossmatching methods, a point-of-care gel agglutination method has recently become available for use in dogs and cats. Crossmatching reduces the risk of hemolytic transfusion reactions but does not completely eliminate the risk of other types of transfusion reactions in veterinary patients, and for this reason, all transfusion reactions should be appropriately documented and investigated.
Conclusion – The administration of blood products is a resource-intensive function of veterinary medicine and optimizing patient safety in transfusion medicine is multifaceted. Adverse reactions can be life threatening. Appropriate donor screening and collection combined with pretransfusion testing decreases the occurrence of incompatible transfusion reactions.     

基于ADAMS的齿轮变速箱动态特性仿真分析

基于三维造型软件Pro／E构建BJ2020型齿轮变速箱的实体模型,并将其导入到ADAMS中,添加约束和载荷后建立变速箱虚拟样机模型,根据变速箱在二档时的实际工况,对其进行动力学仿真,得到输出轴转速、各级齿轮啮合力及啮合频率。仿真结果与理论计算值对比数据较吻合,验证了仿真的准确性。     

Analysis of a steel tubular column filled with equidistant fiber reinforced polymer ring stiffening concrete

Based on theory of cylinders subjected to uniform internal pressure, the mechanical performance of a steel tubular column filled with equidistant fiber reinforced polymer (FRP) ring stiffening concrete is investigated. The solutions for the stress and displacement are regarded as the superposition of elementary and improved solutions. The elementary solutions are found by using two dimensional elastic theory. The improved solutions are found by using the Love displacement function method. Considering the conditions of the displacement continuum of the FRP ring and the steel tube exterior, a more accurate solution for an equidistantly FRP ring stiffened cylinder subjected to a uniform internal pressure is obtained. Several numerical calculations are also carried out. The results indicate the solutions possess good convergence.     

Dynamic analysis and optimization of gear trains in a megawatt level wind turbine

Through coupling vibration analysis of the transmission system of a 1.5 MW wind turbine gearbox, a torsional vibration model of a gear drive system in wind turbines is established. The fourth order Runge Kutta integration method is applied to calculate the dynamic response of a gear system caused by wind loads, time varying meshing stiffness, and system damping. The harmonic balance method is used to find the analytic solution. Based on the solution, a mathematical model for optimum gear system design is established. The model aims at minimizing the vibration acceleration of the planet gear and the total mass of the gear transmission system. The optimization toolbox in MATLAB program is adopted to obtain the optimal solution. A calculated example shows that the primary natural frequency of the gear system has been raised, the dynamic properties of the gear train have been improved remarkably, and the total mass of the gear train has been decreased.     

浅谈高校学报特色栏目的建设

特色化是今后期刊发展的新要求。创建特色栏目是高校学报凸显个性、提高质量、扩大影响的必由之路。特色栏目的建设不仅需要一支相对稳定、结构合理、可持续发展的作者队伍,还对编辑提出了较高的要求。编辑的素养和能力是特色栏目成功与否的关键。     

玉米淀粉浸泡水的回用及内循环反应器的应用——以我国西北某企业为例

玉米淀粉生产废水属高浓度有机废水,可生化性好,处理难度大。以我国西北某玉米淀粉生产企业为例,采用离子交换柱将玉米浸泡水提取菲叮,玉米浸泡水回用率达到100%,并在原污水处理站工艺上增加了IC(内循环)反应器,使处理后污水目标水质达到《污水综合排放标准》(GB8978-1996)一级排放标准,大大减少污染物的排放,对控制玉米淀粉生产废水的污染有重要借鉴意义。     

金融危机背景下农业剩余劳动力转移的根本途径

"就业是民生之本"。我国农业剩余劳动力转移就业问题是事关新农村建设和全面小康社会的一个大问题。由于受美国金融危机的影响,城镇大量工人下岗,已经转移的农业剩余劳动力(农民工)也纷纷失业,但是我国还有上亿农业剩余劳动力需要转移就业。在这种情况下,农业剩余劳动力在农村内部转移已经成为其转移就业的根本途径。通过提高农业剩余劳动力的素质、实施"创业工程"、"户籍与土地的联动机制"等配套工作可以为农业剩余劳动力在农村内部转移提供良好的条件。     

齿轮修形原理及应用

介绍了齿廓修形和齿向修形的基本原理,以某大型风力发电齿轮增速箱输出级宽斜齿轮副传动为例,对修形前后轮齿上载荷分布情况进行了对比分析。