列车作用下青藏铁路路基动力响应试验

目的分析研究多年冻土区青藏铁路在列车动荷载作用下路基的稳定性及振动衰减规律．方法选取青藏铁路北麓河段三个典型试验断面,在春季进行了列车荷载作用下的路基动力响应现场试验,采集路基、边坡、道床3处振动数据,统计计算了青藏铁路客车与货车行驶时路基振动的最大和平均加速度幅值,对实测数据进行了功率谱分析．结果路基上货运和客运列车的竖向最大加速度分别为2．2132m／ss^2和2．0004m／ss^2,对应的平均加速度分别为0．1495m／s^2和0．1143m／ss^2,道床上的振动明显减小．在T28次客运列车的作用下,对于断面Ⅲ,C3测点在振动频率为25Hz、38Hz、46Hz,55Hz出现峰值,能量集中在18～53Hz．边坡C4测点振动能量集中在20—65Hz,C5测点的优势频段为20—80Hz．结论路基上货运列车的振动比客运列车振动大,同一断面竖向衰减速度大于横向,素土路基各方向衰减小于块石路基,下一测点加速度峰值大致减小为相邻上一测点的1／10．     

电厂直接空冷系统风机桥强迫振动响应测试研究

为掌握直接空冷风机系统在不同运行工况下风机桥的振动加速度响应情况,以及加速度频谱特性,制作了空冷系统风机桥1∶1试验模型.对风机桥进行真实扰力加载,运用振动测试设备对风机桥各测点的加速度时程和加速度频谱进行了测定.经过分析得出加速度最大值,以及沿桥架的分布规律,并对加速度频谱进行了深入分析,确定出风机桥振动的主要频率成份.最后得出结论,以供工程设计参考.     

行人扶梯荷载作用下悬挑楼盖的振动测试与舒适度评价

针对搭接扶梯的悬挑楼盖在行人扶梯荷载作用下容易产生铅垂向振动,以某商业夹层中的悬挑楼盖为对象,通过现场振动测试,研究扶梯运行、行人数量、行走方向及行人运动状态对悬挑楼盖振动响应的影响,依据测试数据,评价悬挑楼盖振动的舒适度及人员感知度。研究结果表明：行人步频是影响悬挑楼盖振动的主要因素,而扶梯运行与否则是次要因素;多人在扶梯上以同一步频双向行走时,对悬挑楼盖产生的振动响应较单向行走时有明显削弱的现象;采用峰值加速度对悬挑楼盖进行舒适度评价,当行人在扶梯上跑动时,悬挑楼盖的振动响应易超出舒适度限值;采用KB（Konstant Beurteilungswerte）值对悬挑楼盖进行感知度评价,当行人相对扶梯静止时,悬挑楼盖的振动不会超出感知度容许值,当行人相对扶梯走动或跑动时,悬挑楼盖的振动则会超出感知度容许值。     

线性结构地震反应分析模型研究

对线性结构地震反应分析所使用的有限元分析模型的计算精度进行了详细的讨论,通过数值算例对比研究了使用不同的有限元质量矩阵对线性结构地震反应计算结果的影响,得出了一些有益的结论,可供计算参考。     

基于LMS算法的自适应滤波器的设计

设计了基于LMS算法的FIR自适应滤波器,采用MATLAB仿真软件对其进行了仿真。根据自顶向下的设计流程,采用DDS技术和流水线设计方法,在Quartus Ⅱ开发平台上采用Verilog HDL语言对其进行了硬件实现。实验结果证明该设计比普通自适应滤波器具有结构简单、易于实现、滤波速度快的优点.     

酶解法制备禾虫多肽液的工艺优化及其脱腥工艺探究

目的 应用单因素和响应面实验优化禾虫的酶解工艺,结合模糊数学法探究一种有效的脱腥方法。方法 以中性蛋白酶为酶解剂,禾虫为主要原料,研究液料比、酶用量、时间、温度、pH对酶解效果的影响。在单因素实验的基础上,以液料比、酶解温度、酶用量为自变量,禾虫多肽液的1,1-二苯基-2-三硝基苯肼（1,1-diphenyl-2-picrylhydrazyl,DPPH）自由基清除率为响应值,通过Box-Behnken响应面法分析不同因素对酶解效果的影响,确定酶解的最优组合,并应用美拉德反应、硅藻土和酵母粉对禾虫多肽液进行脱腥实验,模糊数学法评价3种脱腥处理的效果。结果 根据响应面实验得出禾虫的最佳酶解组合为：液料比1:1 (g/mL)、酶解温度60℃、中性蛋白酶用量2450 U/g,得到酶解液的DPPH自由基清除率47.25%±0.11%;禾虫多肽液脱腥的最佳处理为：酵母粉添加量0.7%,反应温度35℃,反应时间30 min。结论 中性蛋白酶酶解禾虫制备禾虫多肽液并采用酵母粉脱腥效果最佳,为禾虫的精深加工提供借鉴,促进禾虫产业的发展。     

Adaptive Learning with Large Variability of Teaching Signals for Neural Networks and Its Application to Motion Control of an Industrial Robot

Recently, various control methods represented by proportional-integral-derivative (PID) control are used for robotic control.To cope with the requirements for high response and precision, advanced feedforward controllers such as gravity compensator,Coriolis/centrifugal force compensator and friction compensators have been built in the controller.Generally, it causes heavy computational load when calculating the compensating value within a short sampling period.In this paper, integrated recurrent neural networks are applied as a feedforward controller for PUMA560 manipulator.The feedforward controller works instead of gravity and Coriolis/centrifugal force compcusators.In the learning process of the neural network by using back propagation algorithm, the learning coefficient and gain of sigmoid function are tuned intuitively and empirically according to teaching signals.The tuning is complicated because it is being conducted by trial and error.Especially, when the scale of teaching signal is large, the problem becomes crucial.To cope with the problcm which concerns the learning performance, a simple and adaptive learning technique for large scale teaching signals is proposed.The learning techniques and control effectiveness are evaluated through simulations using the dynamic model of PUMA560 manipulator.     

Psychometric properties of the MMPI-2-RF Somatic Complaints (RC1) Scale.

The MMPI-2 Restructured Form (MMPI-2-RF; Tellegen & Ben-Porath, 2008) was designed to be psychometrically superior to its MMPI-2 counterpart. However, the test has yet to be extensively evaluated in diverse clinical settings. The purpose of this study was to examine the psychometric properties of the MMPI-2-RF Somatic Complaints (RC1) scale in a clinically relevant population. Participants were 399 patients diagnosed with either epilepsy or psychogenic nonepileptic seizures on the basis of video–electroencephalograph monitoring. The internal structure of the MMPI-2-RF was evaluated using taxometric, confirmatory factor analysis, and item response theory procedures. Data from 4 content-specific scales directly related to RC1 (Malaise, Gastrointestinal Complaints, Head Pain Complaints, and Neurological Complaints) indicated that the latent construct of somatization is a dimensional variable with a bifactor structure. However, consistent with the scale's construction, a unidimensional model also provided adequate fit. A 2-parameter logistic item response theory model better accounted for observed item responses than did 1- or 3-parameter models. Results suggest that the RC1 scale is most precise for T score estimates between 55 and 90. Overall, the scale appears to be well suited for the assessment of somatization. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Determinants of right–left and top–bottom prevalence for two-dimensional spatial compatibility.

When stimulus and response sets vary along horizontal and vertical dimensions, the horizontal dimension is more dominant than the vertical one, an effect called right–left prevalence. Three accounts have been proposed that attribute the effect to a reduced ability to code vertical locations when horizontal codes are also present, the use of right–left effectors, or a difference in salience of the 2 dimensions. The accounts differ in terms of whether the ability to code and process the 2 dimensions is of limited capacity and whether the prevalence effect is a consequence of the effectors used for responding. The authors report 4 experiments that evaluated these issues. Results indicate that use of right–left effectors is important to the right–left prevalence effect because it increases the salience of the horizontal dimension. However, a top–bottom prevalence effect can be obtained if the vertical dimension is made more salient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

自升式钻井平台下桩过程中横摇响应估算

自升式钻井平台就位下桩作业过程中,由于桩腿下放长度变化范围很大,对平台摇荡性能影响亦较大.为了能在设计阶段预报下桩过程中的横摇性能,确保平台安全作业,本文提出一种可为工程实际所接受的简化方法,用来估算下桩过程中横摇角幅值随着桩腿下放长度的变化.以“40自升式钻井平台”为例进行了计算,计算结果与模型试验数据作了比较,其符合程度是令人满意的.