悬空调频发射系统天线的研究

本文深入研究了悬空调频发射系统的设计与应用。文章对常见的调频天线类型进行了全面的分析与评估,确定了最适合悬空调频发射系统的天线形式,并对不同电气参数和安装方式下的覆盖效果进行了仿真计算。本文的研究成果为调频广播覆盖提供了多角度的解决方案,具有重要的理论与实践意义。

高速且节省空间的线性电动机悬空输送系统──Slimjet

高速且节省空间的线性电动机悬空输送系统──Ｓｌｉｍｊｅｔ袁志毅译王正谦校在日本，适应不同需求的各种实用物流运送自动装置不断发展，住友重工有限公司新开发的悬空输送系统Ｓｌｉｍｊｅｔ适用于生产车间运送零部件和半成品，可提高生产率，输送工件快速、准确、及时...

Three Dimensional Kinematics Analysis of the Independent Suspension Multibody System

Based on the theory of multibody system dynamics, the spatial kinematics analysis of the Mcpherson independent suspension widely used in the car was carried out. A practical and simpler method was provided to reduce the number of the generalized coordinates and constraint functions. By solving the nonlinear equations, the motion of any points in the whole suspension and wheel system can be predicted, including the spatial changes of the wheel alignment parameters which are of great importance to the car performances.

Clinical Study on Suspension Pancreatic-Duct-Jejunum End-to-Side Continuous Suture Anastomosis in Pancreaticoduodenectomy

Objective To study the influence of Suspension Pancreatic-Duct-Jejunum End-to-Side Continuous Suture Anastomosis （SPDJCS） on the incidence of pancreatic fistula after pancreaticoduodenectomy, and to analyze its applicability, safety, and efficacies. Methods A prospective controlled trial was conducted with 165 cases receiving pancreati- coduodenectomy in the Department of Hepatopancreatobiliary Surgery from January 2010 to May 2012. The patients were divided into Group A （end-to-end/end-to-side invaginated anastomosis, n=52）, Group B （end-to-side mucosal anastomosis, n=48）, and Group C （SPDJCS, n=65）. The preoperative data, intra- operative data, and operative outcomes （incidence of pancreatic fistula, operation time, intraoperative blood loss, peritoneal drainage, peritoneal hemorrhage, peritoneal abscess, delayed gastric emptying, pulmonary infection, postoperative infection, blood transfusion, and perioperative mortality） were com- pared among the 3 groups. Results The total incidence of pancreatic fistula was 13.9% （23/165） in all the 165 patients. The inci- dence in Group A and Group B was 23.1% （12/52） and 18.8% （9/48）, both higher than that in Group C [3.1% （2/65）, both P〈0.05]. Group C showed significantly better outcomes than group A and B in terms of the opera- tion time （5.5±1.2 hours vs. 6.1±1.1 hours, 5.5±1.2 hours vs. 6.3±1.5 hours）, volume of blood loss （412.0±205.0 mL vs. 525.0±217.0 mL, 412.0±205.0 mL vs. 514.0±217.0 mL）, and postoperative drainage amount of plasma tubes （175.0±65.0 mE vs. 275.0±80.0 mL, 175.0±65.0 mL vs. 255.0±75.0 mL） （all P〈0.05）, while Group A and Group B displayed no difference in these aspects （P〉0.05）. As complications other than pancreatic fistula were concerned, the three groups were not different from each other （P〉0.05）. Conclusions SPDJCS may have the effect of reducing the incidence of pancreatic fistula after pan- creaticoduodenectomy. It could be safe, practical and convenient technique of anastomosis for pancreaticoje- junostomy.

Stiffness-damping matching method of an ECAS system based on LQG control

A novel method of matching stiffness and continuous variable damping of an ECAS(electronically controlled air suspension) based on LQG(linear quadratic Gaussian) control was proposed to simultaneously improve the road-friendliness and ride comfort of a two-axle school bus.Taking account of the suspension nonlinearities and target-height-dependent variation in suspension characteristics,a stiffness model of the ECAS mounted on the drive axle of the bus was developed based on thermodynamics and the key parameters were obtained through field tests.By determining the proper range of the target height for the ECAS of the fully-loaded bus based on the design requirements of vehicle body bounce frequency,the control algorithm of the target suspension height(i.e.,stiffness) was derived according to driving speed and road roughness.Taking account of the nonlinearities of a continuous variable semi-active damper,the damping force was obtained through the subtraction of the air spring force from the optimum integrated suspension force,which was calculated based on LQG control.Finally,a GA(genetic algorithm)-based matching method between stepped variable damping and stiffness was employed as a benchmark to evaluate the effectiveness of the LQG-based matching method.Simulation results indicate that compared with the GA-based matching method,both dynamic tire force and vehicle body vertical acceleration responses are markedly reduced around the vehicle body bounce frequency employing the LQG-based matching method,with peak values of the dynamic tire force PSD(power spectral density) decreased by 73.6%,60.8% and 71.9% in the three cases,and corresponding reduction are 71.3%,59.4% and 68.2% for the vehicle body vertical acceleration.A strong robustness to variation of driving speed and road roughness is also observed for the LQG-based matching method.

Energy conservation research of dehumidification system for main cable anticorrosion of suspension bridge

The necessity of the main cable anticorrosion for suspension bridge is described, and operating principles and composition of main cable dehumidification system are analyzed. An idea using the waste heat of high temperature outlet air of dehumidification system to heat up regeneration air of rotary-type dehumidifier is put forward in this paper. The concrete scheme is to install a heat exchanger on air-out pipeline of roots blower and air-in pipeline of regeneration electric heater of rotary dehumidifier. Air preheated by the heat exchanger enters regeneration electric heater of rotary-type dehumidifier. Energy conservation of main cable dehumidification system for the Yangtze River highway bridge is calculated, and the results show that energy conservation rate can reach 44 %.

Vehicle height control of electronic air suspension system based on mixed logical dynamical modelling

Due to the coexistence and coupling of continuous variables and discrete events, the vehicle height adjustment process of electronic air suspension system can be regarded as a typical hybrid system. Therefore, the hybrid system theory was applied to design a novel vehicle height control strategy in this paper. A nonlinear mechanism model of the vehicle height adjustment system was established based on vehicle system dynamics and thermodynamic theory for variable-mass gas charge/discharge system. In order to model both the continuous/discrete dynamics of vehicle height adjustment process and the on-off statuses switching of solenoid valves, the framework of mixed logical dynamical(MLD) modelling was used. On the basis of the vehicle height adjustment control strategy, the MLD model of the adjustment process was built by introducing auxiliary logical variables and auxiliary continuous variables. Then, the co-simulation of the nonlinear mechanism model and the MLD model was conducted based on the compiling of HYSDEL. The simulation and experimental results show that the proposed control strategy can not only adjust the vehicle height effectively, but also achieve the on-off statuses direct control of solenoid valves.