板坯结晶器振动系统的升级改造

介绍了天钢炼钢厂3#板坯连铸机对结晶器振动系统由变频驱动改造为液压驱动的升级改造过程,着重对自动控制系统在结晶器液压振动系统中所起到的作用进行了分析,并对改造后的效果进行了总结。     

φ4 m×10.7 m卧式PS炼铜转炉的改造

介绍了金隆铜业公司转炉加长改造的内容及特点,重点阐述了改造中转炉驱动系统方案的选择设计及采用伞齿-圆柱齿减速机的效果。     

φ4m×10．7m卧式PS炼铜转炉的改造

介绍了金隆铜业公司转炉加长改造的内容及特点，重点阐述了改造中转炉驱动系统方案的选择设计及采用伞齿—圆柱齿减速机的效果。     

竖井罐笼提升系统安全设施的改造实践

针对竖井罐笼提升系统安全设施采用液压或气压驱动方式存在的初期投资大、运行费用高、安装改造周期长等问题,提出了新型驱动方式,即采用电液推杆作为阻车器及摇台的动力,采用减速电动机作为安全门的动力,对矿井提升系统安全设施进行改造,改造系统应用取得了良好的运行效果。     

西门子S120驱动系统在冷轧圆盘剪改造中的应用

介绍了西门子S7-300及S120驱动控制系统在攀钢冷轧厂横切机组圆盘剪改造中的应用。利用西门子的S120驱动系统及S7-300实现圆盘剪的高精度定位控制。     

采用“三合一”减速机,改造堆取料机走行系统

针对当前在用的堆取料机走行系统由于设计不合理造成故障较多等问题,经过大修改造,把侧向悬挂式安装的走行差速行走驱动改为"三合一"减速机及变频调速驱动。解决了走行系统在实际运行过程中的一系列问题,确保了堆取料机在生产运行过程中的稳定可靠。     

干熄焦提升设备变频传动系统国产化改造关键技术研究及应用

干熄焦提升机是干熄焦工艺的关键大型装备,对变频器的驱动系统要求很高,驱动系统一直为国外进口品牌所垄断,因此突破干熄焦提升机组变频传动系统国产化改造关键技术,实现国产化替代具有非常重要的意义。本文详细分析了干熄焦提升机的工艺特点以及设备对变频调速系统的性能要求,实现了国产化改造的核心关键技术突破,现场改造取得了非常满意的效果。     

带预给料的定量给料机的应用

分析了定量给料系统的原理、配置及控制过程,系统配置在满足“申克标准规范”的前提下,阐述了在铜精矿高粘度、大仓压的情况下,对下料漏斗及驱动机构所进行的改造。     

内力驱动在电炉包厢小车上的运用

本文就电炉包厢小车的驱动部改造过程 ,进行了详细阐述 ,并由此对内力驱动及外力驱动这两种驱动方式进行了比较。     

大型轧机液压升降台的改造

对传统的大型轧机升降台结构形式及控制方式进行了改造设计，采用平衡缸和升降缸相结合的驱动方式，解决了液压系统在高压、大流量下的缓冲及升降台的位置检测精度     

Cognitive impairment and social distress as different pathways to depression in the elderly: a cross-sectional study

BACKGROUND: The qualities of visual perception and of motor reaction to the visual stimulus have never been studied in reference to the type of video-camera system (2-D vs 3-D) used during laparoscopy. METHODS: The study was designed in two parts. The first evaluated the ability of the eye to discriminate how objects are spaced relative to one another. The second investigated the motor reaction to the visual stimulus in an environment where depth was the preponderent cue. The tests were performed in a pelvi-trainer in which were inserted different modules built either for visual observation (Part 1) or for evaluation of motor ability (Part 2). Variables studied during Part 1 were the time required to do the test and the number of errors committed during its performance. The variable evaluated during Part 2 was the time needed to terminate the test. Each of these two parts of the study were completed alternating the 2-D and 3-D systems. A total of 304 observations were recorded. Statistics used were the paired t-test, the independent group t-test, and the Newman-Keuls multiple comparisons test. RESULTS: Results of Part 1 of the study confirm that visual perception varies significantly among individuals (n = 10) (p < 0.05) and that a true 3-D video-camera system facilitates visual perception when compared to a 2-D system (p < 0.001). Results of Part 2 of the study also show significant differences among participants (n = 9)(p < 0.05). The true 3-D system allowed significantly faster motor performances than the 2-D system (p < 0.001). CONCLUSION: Our experiment shows that the 3-D system allowed significant improvements in the execution of the evaluated parameters. Also noted were significant differences among participants in term of visual and motor skills.     

关于中厚板全液压矫直机液压系统驱动电机功率的选取

在计算中厚板全液压矫直机液压系统驱动电机功率时,存在选取液压系统压力和流量数值不精确等问题,导致计算所得电机功率过大,设备资源浪费。针对这些问题,提出一种根据液压系统载荷谱选取压力和流量的方法,以计算系统电机功率,即根据载荷谱,通过分析不同工况下系统的工作状态,选取该工况下所需液压系统的压力和流量,计算得出该工况所需的电机功率。通过现场采集数据验证了以这种方法计算出的电机功率能够满足实际生产需要,新得到的电机功率值小于原先使用的电机功率,可达到节约能源的目的。     

CTM——1500——2型同步电动机励磁系统技术改造

对ＣＴＭ－１５００－２型同步电动机励磁系统现状进行了调查分析,在励磁机的基础上,采取增加励磁柜的措施,使两套系统均能工作,从而保证同步电动机的安全运行。     

Cooperative mechanisms between leg joints of Carausius morosus II. Motor neuron activity and influence of conditional bursting interneuron

The activity of the motor neuron pools of the protractor coxae muscle and of the thoracic part of the depressor trochanteris muscle during forward walking in the stick insect was investigated, and a spiking local interneuron, able to produce "endogenous bursting" and innervating both motor neuron pools, was identified. Extracellular recordings of the motor neurons innervating the protractor and the thoracic depressor of front, middle, and rear legs, respectively, were made with oil-hook electrodes from the peripheral nerves nl2c and nl4a while the animals were walking on a styrofoam treadwheel. The corresponding leg movements were registered and phase histograms were created with the software Spike2. Intracellular recordings were made in the neuropile of the metathoracic ganglion with glass electrodes filled with the dye Lucifer yellow. In all three legs measured (front, middle, and rear), both motor neuron pools increased their activity during the swing movement. The increase in the activity of the protractor motor neurons started at the end of the stance approximately 100 ms before reaching the posterior extreme position (PEP), and the activity of the large-sized depressor motor neurons increased as soon as the tarsus was lifted at the PEP. A local spiking interneuron was identified that excited both motor neuron pools. In 4 of 23 recordings the interneuron started to burst in synchrony with protractor and thoracic depressor motor neurons. During bursting a depolarizing stimulus reinforced and a hyperpolarizing stimulus inhibited the activity of both motor neuron pools. Thus we conclude that the thoracic part of the depressor trochanteris muscle might be a component of the neuromuscular system that shapes the swing movement. The two proximal joints, subcoxal and coxa-trochanter, connected mechanically via the thoracic part of the depressor trochanteris muscle, are also connected neurally by segmental and intersegmental spiking interneurons (this paper) and by nonspiking local interneurons (see companion paper).     

Determination of degradation rates of transfer and ribosomal ribonucleic acids in cultured rat hepatocytes by measuring N6-threoninocarbonyladenosine, dihydrouridine, and pseudouridine in medium using high-performance liquid chromatography

The cause of the selective degeneration of motor neurons in amyotrophic lateral sclerosis (ALS) remains unexplained. One potential pathogenetic mechanism is chronic toxicity due to disturbances of the glutamatergic neurotransmitter system, mediated via alpha-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid (AMPA)-sensitive glutamate receptors. Functional AMPA receptors consist of various combinations of four subunits (designated GluR1-4). The GluR2 subunit is functionally dominant and renders AMPA receptors impermeable to calcium. Most native AMPA receptors in the mammalian central nervous system (CNS) contain the GluR2 subunit and are calcium impermeable. We have investigated the composition of AMPA receptors expressed on normal human spinal motor neurons by in situ hybridization to determine their likely subunit stoichiometry. Highly significant levels of mRNA were detected for the GluR1, GluR3, and GluR4 subunits. However, GluR2 subunit mRNA was not detectable in this cell group. The absence of detectable GluR2 mRNA in normal human spinal motor neurons predicts that they express calcium-permeable AMPA receptors unlike most neuronal groups in the human CNS. Expression of atypical calcium-permeable AMPA receptors by human motor neurons provides a possible mechanism whereby disturbances of glutamate neurotransmission in ALS may selectively injure this cell group.     

纯电动汽车车载电源性能在环测试平台研究

为研究纯电动汽车车载电源性能,提出并搭建了由异步电动机和直流电动机组成的在环测试平台.异步电动机用来模拟纯电动汽车的牵引电动机,直流电动机用来模拟汽车行驶时的阻力和惯量,对异步电动机和直流电动机分别实施转速控制和转矩控制.分析了电动汽车行驶工况,给出了简单循环工况下参考转速、转距和功率.设计了异步电动机调速系统转速控制器和电流控制器,建立了异步电动机调速系统的数学模型,提出了基于自适应模糊神经网络控制的异步电动机调速系统.仿真和实验结果表明,基于自适应模糊神经网络控制的调速系统明显优于PID控制的交流调速系统,在环测试平台能够较好跟踪参考转速和参考转距的变化.      

Pharmacology of descending noradrenergic systems in relation to motor function

The function of descending noradrenergic systems in the spinal ventral horn has not been fully elucidated. We have reviewed our own findings and those of others relating to motor function of these noradrenergic systems. We studied the effects of adrenergic drugs on spinal reflexes, decerebrate rigidity, and noradrenaline release from the spinal cord in rats, and motoneuron activity in spinal cord slices isolated from adult rats. It was shown that the descending noradrenergic systems were facilitatory to the motor system, and that alpha 1-antagonistic action at the spinal cord and alpha 2-agonistic action at the brainstem inhibited spinal motor activity by blocking spinal alpha 1-receptors and by reducing the release of noradrenaline in the spinal cord, respectively.     

Effect of pairing red nucleus and motor thalamic lesions on reaching toward moving targets in cats.

The small effects of bilateral lesions of motor thalamus on motor control and the transient deficits induced by bilateral kainic red nucleus (RN) lesions have been explained by a parallel competitive role of the cortico- and rubro-spinal pathways: Either pathway can take over motor control if the other is damaged. In this study the effect of bilateral and simultaneous lesions of both RN and motor thalamus was analyzed on cats overtrained to reach toward a moving target. After lesion, accuracy was impaired, movement onset was delayed, and movement execution was perturbed. However, postoperative retraining led to full recovery of the preoperative accuracy level although movement latency remained higher. The relative mildness of the long-lasting deficit after lesioning 2 main motor brain structures underlines the robustness of overlearned movements and widens the idea of parallelism in the motor system to other (subcortical?) pathways. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

大功率轧机控制系统的分析与研究

目前,钢铁企业多采用交流调速的方法进行轧机的传动控制。本文的分析研究基于交—直—交变频的同步电动机矢量控制系统,通过仿真验证了同步电动机矢量控制系统的优越性,为轧机传动控制提供技术参考。