振动攻丝参数匹配数据库系统的设计与开发

针对振动攻丝工艺参数与攻丝扭矩之间的非线性关系,提出利用Delphi提供功能强大的数据库开发工具,以振动攻丝实验数据为基础,借助于神经网络的基本原理建立低频振动攻丝参数匹配的数据库系统,实现了根据参数组合预测攻丝扭矩值和根据扭矩值查询参数组合.介绍了该数据库系统的结构和功能及设计开发技术,并通过实验验证了该数据库系统的可行性.     

振动攻丝的系统设计

本介绍了振动攻丝的原理和特点，探讨由PC系统微机构成的步进电机控制及数据采集分析系统，以及实验系统的软件结构，硬件接口和步进电机的高频正反转的控制方法。最后还阐明了振动功丝的实验方法和数据处理方法。     

振动攻丝的系统设计

本文介绍了振动攻丝的原理和特点,探讨由PC系统微机构成的步进电机控制及数据采集分析系统,以及实验系统的软件结构,硬件接口和步进电机的高频正反转的控制方法。最后还阐明了振动功丝的实验方法和数据处理方法。     

行星齿轮传动中齿数对行星轮载荷的影响

从齿轮时变啮合刚度出发，建立了单级2K-H渐开线行星齿轮传动的集中质量参数型振动模型，以行星架作为参考坐标，将齿轮啮合的刚度近似成时变分段线性的弹簧刚度，采用模态叠加的原理，通过系统在刚度变化时的速度以及位移的连续性条件，在时域范围内模拟系统的振动过程。分析了不同齿数齿轮对啮合力的影响，最后得出：在2K-H渐开线行星齿轮传动中，若太阳轮与内齿圈均为行星轮个数的整数倍时，行星轮的均载效果好；太阳轮与内齿圈的齿数不为行星轮个数的整数倍时，行星轮之间出现偏载；系统有数个与初始刚度相关的稳定点的结论。     

机床工艺系统静刚度计算机测试系统的研究

介绍了机床工艺系统静刚度的概念。提出了静刚度测试系统的总体设计方案，并对该系统主要软件和硬件部分进行了说明与开发。     

斜齿轮副结构参数灵敏度分析

以机械传动系统中的斜齿轮啮合为研究对象,在考虑时变刚度、齿侧间隙和啮合误差的情况下,建立了十自由度斜齿轮非线性振动数学模型。以斜齿轮结构参数作为灵敏度分析参数,采用数值分析方法分别研究了斜齿轮系统振动加速度均方根值对齿轮质量、支撑刚度和支撑阻尼的灵敏度。结果表明:主、被动轮横向（y向）振动对各参数敏感度较低,横向振动（x向）与被动轮扭转振动对质量参数、刚度参数、阻尼参数较为敏感,被动轮扭转振动受到阻尼的影响很大,灵敏度在扭转振动固有频率处变化较大。     

基于负刚度结构的驾驶室座椅悬架系统设计与评价（英文）

为了改善驾驶室座椅的隔振性能,提出了基于负刚度结构的工程机械驾驶室座椅悬架系统优化模型.通过设计座椅负刚度悬架结构(NSS),建立了负刚度非线性动力学方程,基于MATLAB对悬架系统的不同参数及其对动刚度的影响进行了分析,得到悬架系统最为理想的配置参数范围;同时提出了NSS优化模型,采用不同方法对振动传递特性进行了仿真分析.研究结果表明:优化后的座椅悬架系统的位移幅值与加速度幅值均明显减小,座椅垂直振动方向的四次功率振动剂量值与加权加速度均方根值分别下降了86%和87%,座椅有效振幅传递率和悬架系统振动传递率均下降,传递给驾驶员的振动的峰值频率均不在容易引起人体不适的关键频率值附近.这表明座椅悬架系统的设计对驾驶员受振后的身体健康状况没有任何影响,NSS悬架系统具有良好的隔振性能,提高了驾驶员的乘坐舒适度.     

船舶结构振动开放性教学实验

围绕船舶总体振动的特点，研究开发了船舶振动的模态特性和浮筏减振特性的开放设计性教学实验，了解船体振动模态与船舶装载的关系，以及船上浮伐系统的惯性、刚度和阻尼对减振效果的影响，使得船舶与海洋工程专业的本科生能够通过开放性实验，加强学生对船舶总体振动特性的理解，提高分析问题和创新能力。     

基于负刚度结构的驾驶室座椅悬架系统设计与评价

为了改善驾驶室座椅的隔振性能,提出了基于负刚度结构的工程机械驾驶室座椅悬架系统优化模型.通过设计座椅负刚度悬架结构(NSS),建立了负刚度非线性动力学方程,基于MATLAB对悬架系统的不同参数及其对动刚度的影响进行了分析,得到悬架系统最为理想的配置参数范围;同时提出了NSS优化模型,采用不同方法对振动传递特性进行了仿真...     

非比例阻尼系统自由振动的一种近似求解方法

提出了求解具有非比例阻尼多自由度振动系统自由振动的近似方法。由于阻尼矩阵和质量矩阵以及刚度矩阵相比很小,把系统正则变换后,我们可以把模态阻尼矩阵看作小量,这样我们用多尺度方法求出非比例阻尼系统近似解析解。     

全自动多工位钻孔攻丝倒角机的设计

为解决小尺寸电器插脚钻孔、攻丝、倒角工序多,人工作业效率低且产品质量不稳定等问题,设计了一种全自动多工位钻孔攻丝倒角机。该设备包括送料装置、夹紧装置、加工装置和电气控制系统等。设备的优点是,工人只需将插脚放入振动盘筛选,送料装置将工件输送至各工位自动完成钻孔倒角、攻丝工序,最后检测加工完成零件,自动计数并将工件移出,整个过程无需人工介入,有效提高了生产效率和产品质量。     

Dyslexia and dysgraphia: more than written language difficulties in common

A dual-task paradigm involving concurrent finger tapping and line orientation judgment was used to investigate brain processing differences in early adolescent good readers/poor spellers (dysgraphia), poor readers/poor spellers (dyslexia) and good readers/good spellers. Whereas all groups were similarly affected during the left-hand tapping condition, in the right-hand tapping condition the good spelling group displayed significantly less tapping disruption than both poor spelling groups, who did not differ significantly from each other. From these results, it can be inferred that individuals with dyslexia and dysgraphia share a left-hemisphere processing limitation that is not confined to written language. In light of other relevant research findings, I suggest that this limitation is due to the absence of a disembedding scanning mechanism for converting spatial arrays (e.g., spelling patterns) to temporal form-an impairment putatively caused by attempting to teach written language to children who are late in establishing left-hemisphere motor dominance.     

刚性镗削主轴刚度对加工精度的影响

根据轴端挠度计算公式讨论了刚度与被加工孔精度之间的关系,得出了几个结论,提出了提高主轴静刚度的途径。     

Secondary-Task Effects on Learning With Multimedia: An Investigation Through Eye-Movement Analysis

This study investigates secondary-task interference on eye movements through learning with multimedia. We focus on the relationship between the influence of the secondary task on the eye movements of learners, and the learning outcomes as measured by retention, matching, and transfer. Half of the participants performed a spatial tapping task while studying the instructional materials, whereas the other half studied the materials, without spatial tapping. The results revealed suboptimal learning outcomes under the secondary task, which was accompanied by fewer transitions of gaze between the text and the figure. We propose that the suboptimal learning outcomes might be due to the disrupted processing of pictures, and possibly due to the less efficient integration, of the information gathered from the text and figures.     

基于ANSYS某型数控钻床整体结构分析

利用ANSYS有限元分析软件先分别建立数控钻床的主要部件的实体模型,再通过组装命令建立起整机的实体模型,最后对钻床进行有限元静力分析,通过静力分析虚拟检验机床的静刚度及钻床的主要加工性能指标,为机床的虚拟设计提供了一种分析手段.     

带钢热连轧机液压AGC变刚度分析

文章论证和分析了本钢引进的德国AEG公司厚度控制模型算法与我国自行研制的动态设定型变刚度理论之间的关系,从而证明了动态设定型变刚度原理用于本钢热连轧厂的液压压下系统是可行的,并实现了变刚度控制。     

基于差异沉降控制的基础设计方法研究

沉降缝、后浇带和整体连接是控制建筑物各部分之间发生差异沉降的主要做法。参照工程实例,总结了三种现行方法的构造、特点及其应用。分析表明：沉降缝安全合理,但后续施工中对缝隙的盖缝处理较难;后浇带是建筑与结构设计中针对差异沉降采用的折中方案,在一定范围内能起到较好的效果;整体连接方式通过基础及结构的刚度来调整不均匀沉降,施工方便,但对基础的要求较高,有待进一步的理论研究分析和工程实践检验。伴随着计算机数值分析技术的发展,整体连接方式必将得到广泛应用。     

对智能开发的理论思考

智能开发是一个倍受关注的焦点问题，其经验与教训俱存。思考智能开发的理论问题，把握科学的智能观、智能开发观，认识智能开发的研究问题及其开发原则，有助于智能开发的理论与实践的发展。     

Timing precision and rhythm in developmental dyslexia

Current research on the etiology ofdevelopmental dyslexia is generally informed byeither of two major hypotheses. One of theseassumes that the phonological processing ofconsonants and vowels at a segmental levelidentifies the core deficit in developmentaldyslexia and that it cannot be reduced todomain-general deficits of temporal informationprocessing. The other hypothesis holds thatphonological processing deficits aresymptomatic of an underlying, domain-generaldysfunction; and that at least some dyslexiasubtypes are causally related to domain generaldeficits of temporal information processing forauditory and visual stimuli. This report startsfrom the assumption that the terms temporal information processing andphonological processing as applied in currentdyslexia research, are frequently conflated. Further, it assumes that the conflated termsmust be decomposed into their concretebehavioral referents before the causalsignificance of either can be investigatedsystematically.The studies to be summarized in thisreport represents one step toward suchdecomposition. The findings indicated thatduring a motor sequencing task, dyslexicstudents anticipated the signal of anisochronic pacing metronome by intervals thatwere two or three times as long as those ofage matched normal readers or normal adults.These group differences were significant whenparticipants tapped with the preferred indexfinger alone or with both fingers in unison.Dyslexic students also took significantlylonger than normal readers did to recalibratetheir tapping responses when the metronome ratewas experimentally changed in the middle of atrial.In addition, dyslexic students, bycontrast to normal readers, had inordinatedifficulty reproducing simple motor rhythms byfinger tapping, and similar difficultyreproducing the appropriate speech rhythm oflinguistically neutral nonsense syllables.These difficulties were exaggerated whenparticipants had to synchronize theirperformance to an external pacing metronome.The implications of the findings for temporalinformation processing deficits on one hand,and impaired phonological processing on theother, are discussed.