考虑路基剪切效应的高速铁路有砟轨道-车辆系统移动元分析

为在现有三层离散支撑梁有砟轨道模型中考虑路基土体间的剪切效应,在Pasternak双参数地基模型基础上对剪切层进行离散处理,采用移动单元法建立了考虑路基土体剪切效应的有砟轨道-车辆耦合动力学模型,将移动单元法与MATLAB相结合,编制计算程序,通过MATLAB数值计算,研究路基剪切效应对车-轨耦合系统的影响,以及轨道不平顺和轨枕空吊对系统动力特性的影响规律。研究结果表明,考虑路基剪切效应时,钢轨、轨枕、道砟的位移响应均有不同程度的减小,并且抑制情况从钢轨到道砟相差逐渐增大,三者的加速度响应也均有较为明显的下降,其对加速度响应的抑制效果从道砟到轨枕依次减小,但钢轨的加速度减幅大于道砟,对轮轨接触力有一定影响,但影响不明显,减幅仅为0.85%;不平顺幅值和波长特性对系统的动力响应会产生显著影响,随着幅值增大和短波成分增加,系统动力响应加剧,其中2 m左右短波不平顺和90%百分位数谱对轮轨动力特性影响显著;列车经过空吊区域时,空吊及周围区域轨道结构动力响应会发生突变,导致系统动力响应超过限值。建立的基于移动单元法的有砟轨道-车辆耦合模型及相关分析可为高速铁路的振动分析提供参考依据。

改良性柑橘果胶通过下调Galectin-3抑制膀胱癌细胞生长

目的检测改良性柑橘(MCP)对人膀胱癌增殖和生长的抑制作用。方法 MTT检测膀胱癌细胞T24和J82细胞的活性。Western blot检测T24和J82细胞中凋亡蛋白cv Caspase-3和cv PARP以及Galectin-3蛋白的表达水平。建立膀胱癌T24细胞皮下移植瘤裸鼠模型,灌胃MCP后,比较各组肿瘤重量和体积大小,免疫组化的方法检测各组别的增殖蛋白Ki67和凋亡蛋白cv Caspase-3以及Galectin-3蛋白表达水平的差异性。显微镜观察分析结果。结果 MTT结果证实MCP对人膀胱癌细胞T24和J82细胞活力有抑制作用(P<0.05)。Western blot证实浓度为2.0%的MCP组别中膀胱癌细胞凋亡蛋白表达明显增高。灌胃MCP对T24移植瘤荷瘤裸鼠的肿瘤体积和重量均有明显的抑制(P<0.05),免疫组织化学染色定量分析表示700mg/kg组荷瘤鼠组织内Ki67和Caspase-3证实增殖指数降低(P<0.05),其潜在靶点Galectin-3表达降低。结论本课题研究显示MCP对膀胱癌细胞的增殖和存活的显著抑制作用,且Galectin-3表达降低。故MCP作为一种天然的膳食纤维,同样可以作为药物预防和治疗膀胱癌。

Unbalance Vibratory Displacement Compensation for Active Magnetic Bearings

As the dynamic stiffness of radial magnetic bearings is not big enough, when the rotor spins at high speed, unbalance displacement vibration phenomenon will be produced. The most effective way for reducing the displacement vibration is to enhance the radial magnetic bearing stiffness through increasing the control currents, but the suitable control currents are not easy to be provided, especially, to be provided in real time. To implement real time unbalance displacement vibration compensation, through analyzing active magnetic bearings （AMB） mathematical model, the existence of radial displacement runout is demonstrated. To restrain the runout, a new control scheme-adaptive iterative learning control （A1LC） is proposed in view of rotor frequency periodic uncertainties during the startup process. The previous error signal is added into AILC learning law to enhance the convergence speed, and an impacting factor/3 influenced by the rotor rotating frequency is introduced as learning output coefficient to improve the rotor control effects, As a feed-forward compensation controller, AILC can provide one tmknown and perfect compensatory signal to make the rotor rotate around its geometric axis through power amplifier and radial magnetic bearings. To improve AMB closed-loop control system robust stability, one kind of incomplete differential PID feedback controller is adopted. The correctness of the AILC algorithm is validated by the simulation of AMB mathematical model adding AILC compensation algorithm through MATLAB soft. And the compensation for fixed rotational frequency is implemented in the actual AMB system. The simulation and experiment results show that the compensation scheme based on AILC algorithm as feed-forward compensation and PID algorithm as close-loop control can realize AMB system displacement minimum compensation at one fixed frequency, and improve the stability of the control system. The proposed research provides a new adaptive iterative/earning control algorithm and control strategy for AMB displacement minimum compensation, and provides some references for time-varied displacement minimum compensation.

Dynamic Responses of Rotor Drops onto Double-decker Catcher Bearing

In an active magnetic bearing （AMB） system, the catcher bearings （CBs） are indispensable to protect the rotor and stator in case the magnetic bearings fail. Most of the former researches associated with CBs are mainly focused on the dynamic responses of the rotor drops onto traditional single-decker catcher bearings （SDCBs）. But because of the lower limited speed of SDCB, it cannot withstand the ultra high speed rotation after rotor drop. In this paper, based on the analysis of the disadvantages of SDCBs, a new type of double-decker catcher bearings （DDCBs） is proposed to enhance the CB work performance in AMB system. In order to obtain thc accurate rotor movements before AMB failure, the dynamic characteristics of AMB are theoretically derived. Detailed simulation models containing rigid rotor model, contact model between rotor and inner race, DDCB force model as well as heating model after rotor drop are established. Then, using those established models the dynamic responses of rotor drops onto DDCBs and SDCBs are respectively simulated. The rotor orbits, contact forces, spin speeds of various parts and heat energies after AMB failure are mainly analyzed. The simulation results show that DDCBs can effectively improve the CBs limit rotational speed and reduce the following vibrations, impacts and heating. Finally, rotor drop experiments choosing different types of CBs are carried out on the established AMB test bench. Rotor orbits, inner race temperatures as well as the rotating speeds of both inner race and intermediate races after rotor drop are synchronously measured. The experiment results verify the advantages of DDCB and the correctness of theoretical analysis. The studies provide certain theoretical and experimental references for the application of DDCBs in AMB system.

HIGH TEMPERATURE DISPLACEMENT SENSOR

A high temperature displacement sensor based on the principle of eddy-current is investigated. A new temperature compensation technique by using eddy-current effect is presented to satisfy the special requirement at high temperature up to 550℃. The experiment shows that the temperature compensation technique leads to good temperature stability for the sensors. The variation of the sensitivity as well as the temperature drift of the sensor with temperature compensation technique is only about 7.4% and 90-350 mV at 550 ℃ compared with that at room temperature, and that of the sensor without temperature compensation technique is about 31.2% and 2-3 V at 550 ℃ compared with that at room temperature. A new dynamic calibration method for the eddy-current displacement sensor is presented, which is very easy to be realized especially in high frequency and at high temperatures. The high temperature displacement sensors developed are successfully used at temperature up to 550 ℃ in a magnetic bearing system for more than 100 h.

黎族传统建筑元素在美丽乡村导视系统中的应用

本文首先对黎族传统建筑具有代表性的落地式船型屋、干栏式船型屋、黎族谷仓等进行分析,然后阐述黎族传统建筑元素在美丽乡村导视系统中的应用意义,最后阐述黎族传统建筑元素在美丽乡村导视系统中的应用思路。以期为美丽乡村导视系统设计提供一定的借鉴。

海南旅游企业集团品牌整合设计研究

随着海南旅游企业集团的组建,其品牌在建设过程中产生了诸多问题。首先,本文对品牌整合设计相关内容进行了阐述,并分析了海南旅游企业集团品牌设计现状;其次,针对其问题从品牌管理模式、品牌视觉形象和品牌传播体系三个角度提出相应的策略。通过本文的研究,以期能够健全海南旅游企业集团品牌设计体系,完善品牌传播形式,提升企业集团竞争力,使其在复杂而多变的社会环境中脱颖而出,更好地助力海南自由贸易港建设。

基于根因分析法建立乳腺癌术后患者早期肢体康复方案

目的探讨基于根因分析法建立乳腺癌术后患者早期肢体康复方案的应用效果, 以提升乳腺癌术后患者早期康复意愿, 提高护士肢体康复认知, 降低乳腺癌术后对身体功能造成的伤害。方法运用根因分析法找出影响乳腺癌术后患者早期肢体康复的相关原因并分析, 成立多元创新团队, 制定乳腺癌术后患者早期肢体康复的接力流程, 借助线上教育资源, 设计饱含趣味性的康复运动训练, 如游戏、九宫格等运动方案。结果乳腺癌术后患者早期肢体康复干预率由16%提升至100%, 患者满意度由68%提升至98%, 护士肢体康复认知正确性由72.4%提升至100%, 差异均有统计学意义(P<0.05)。结论基于根因分析法建立乳腺癌术后患者入院早期肢体康复方案, 患者和护士参与早期康复的主动性及患者对肢体康复满意度均得到提升, 提高护士对早期肢体康复的认知, 对患者预后有重要意义。

三支承磁悬浮轴承的不对中特性

应用多个磁悬浮轴承支承的转子系统,由于机械加工以及安装等方面的误差会导致各个磁悬浮轴承之间有一定的不对中量。提出了将转子偏离磁轴承中心悬浮,以减小各个支承悬浮位置的不对中量;结合单自由度磁轴承控制原理,分析了转子悬浮位置偏离中心对磁轴承悬浮性能的影响;从理论和试验两个方面对比研究了3个不对中磁悬浮轴承支承的转子悬浮在磁轴承中心和偏离中心后磁轴承的控制电流和抗扰动性能。研究结果表明一定程度的偏离磁轴承中心悬浮能够提高磁悬浮轴承系统的稳定性。