钼合金钻孔加工中钻削轴向力实验研究

对钼合金钻孔过程中不同钻削参数下的钻削轴向力和钻削扭矩进行了实验测量,并对进给速度和主轴转速对钻削轴向力和钻削扭矩的影响进行了分析。结果表明:当进给速度一定而主轴转速变化时,钻削轴向力随钻削速度增加而略有减小,钻削扭矩随主轴转速增加而减小。当主轴转速一定而仅进给速度变化时,钻削轴向力和钻削扭矩均随进给速度增加而增加,进给速度的变化对钻削轴向力和钻削扭矩的影响要比主轴转速变化的影响更显著。     

KR过程铁水包底部倾斜对铁水混匀现象影响的水模型研究

以210 t铁水包为原型建立1∶7的水模型，研究底部倾斜对KR过程铁水混匀现象的影响。研究了铁水包底部倾斜时搅拌桨转速和浸入深度对混匀时间、漩涡、液相中粒子分散和扭矩的影响，并与平底铁水包进行了对比。结果发现，包底倾斜17.5°时，混匀时间较平底时减少30.6%。搅拌桨转速为110 r/min时，浸入深度增加会导致液相中粒子分散变差，倾底铁水包中粒子分散程度优于平底铁水包。搅拌桨转速为160 r/min时，平底铁水包中粒子分散程度优于倾底铁水包。将平底改为倾底后，同工况下扭矩大幅增加。     

DNJ－3转速检控器的研制

ＤＮＪ－３转速检控器的研制长沙冶金设计研究院王会安，李嘉武ＤＮＪ－３转速检控器是一种与定扭矩联轴节配用，可以测量主副轴转速并以数字显示的新型转速检控器。它设有高低速越限报警及主副轴滑差报警装置。机内有声光报警，也可接至机外，供远距离传送或供系统增加接...     

宽厚板预矫机负扭矩分析

宽厚板七辊预矫机是提高板带平直度、均匀或减小残余应力分布的重要环节,其矫直水平直接决定了产品质量.以宽厚板实际变形情况为背景,通过研究材料变形与各道次下的弯曲曲率及弯曲挠度之间的关系,对负扭矩的产生原因进行了分析;与此同时采用应变电桥法对七辊预矫过程中传动轴扭矩测试信号进行了分析,并通过有限元模拟进行对比分析.研究结果表明:负扭矩的产生是由于集中驱动所提供的同一转速与压弯量不同形成的不均一速度,二者无法适应引起的;负扭矩导致各个辊负载扭矩重新分配,最终对矫直辊面造成损伤;并在此基础上优化矫直工艺参数,将第二台电机的转速提高30％后,6号辊负扭矩现象得到缓解,3号和5号辊扭矩剧增现象得以消除,矫后板平直度得到改善,矫后残余应力分布更加均匀.     

主动旋转顶头的转速对穿孔力参数的影响

实现了2辊斜轧穿孔顶头的主动旋转,测定了顶头转速与穿孔总轧制力、轴向力和顶杆扭矩的关系,讨论了主动旋转顶头穿孔新工艺对毛管质量的影响。     

曲柄滑块式冷轧管机机构动力学性能研究

本文讨论了往复式冷轧管机所采用的曲柄滑块机构转速增加对输入扭矩的影响，并推导出了计算公式，对重新确定所需电机功率、输入轴及其传动齿轮的强度校核等提供了可供应用的数据。同时还对提高速度后对其它动力学性能指标的影响以及此类机构在高速运转情况下可能产生的问题进行了探讨。     

交流伺服电机驱动机械压力机的发展

由于交流伺服驱动压力机目前尚不能胜任大吨位压力成形工艺的需要，因此，研制高容量、大扭矩、低转速交流伺服电机，提高大变负荷下交流伺服驱动系统的效率，开发新的传动机构以满足伺服控制和承载能力的需要是现阶段此项技术发展的关键所在。本文分析了机械压力机交流伺服电机驱动的背景，总结了交流伺服驱动压力机的特点及当前的发展现状。     

切割机齿式联轴器改造

简述方圆坯铸机切割机的构造,详细分析了齿式联轴器的受力情况及损坏原因,应用扭矩、转速理论校核了强度;针对故障原因采取了防范措施,控制了突发事故的发生,保证了设备的正常运行.     

主动旋转顶头的转速对穿孔力参数的影响

在实验室条件下实现了二辊斜轧穿孔顶头的主动旋转,测定了顶头转速对穿孔总轧制力,轴向力和顶杆扭矩的影响。讨论了主动旋转顶头穿孔新工艺对毛管质量的影响。     

盾构机双驱动大功率行星齿轮的传动原理及特性

在研究盾构机及行星齿轮机构的基础之上,针对盾构机刀盘驱动系统,提出一种新型盾构机双驱动大功率行星齿轮传动系统,分析了传动系统的原理及其结构;建立了新型传动系统的运动学模型,对该系统的传动特性进行了分析,获得了系统的传动比、系统内部的转速、扭矩的关系和变化规律;通过对比简化实验得到的结果与理论计算得到的结果,其变化规律基本一致,验证了数学模型及分析方法的正确性.双驱动大功率行星齿轮传动系统具有传动比大、承载能力强的特点,能实现低转速、大扭矩输出的功能,满足盾构机的基本工作要求,不仅可取代传统的多个电机同时驱动多个减速器的传动系统,还能实现3种不同型式的盾构机传动系统功能.     

齿轮箱换挡力矩参数智能测试仪的研制

介绍了一种用于齿轮箱换档力矩参数测试的智能仪表，它以高性能单片机为核心，采用了Ｓ型高精度电阻应变式传感器及放大变换电路，实现了换档力矩参数的自动测量、数据处理数字显示与记录 。     

高强度大六角头螺栓连接副扭矩系数的复验

介绍了高强度大六角头螺桧连接副扭矩系数的复验方法,并分析讨论了影响扭矩系数的相关因素     

Trunk muscle activation and cocontraction while resisting applied moments in a twisted posture

Previous studies of twisting have revealed substantial cocontraction of agonist and antagonist muscles within the torso when torsional moments are generated. The objective of the current study was to quantify the activations and cocontraction of eight trunk muscles as subjects maintained an axially rotated trunk posture and resisted external applied bending moments. Ten subjects twisted their torsos 25 degrees to the right (clockwise) and resisted 20 and 40 Nm bending moments from 12 directions. The moment directions were in a transverse plane and labelled clockwise as viewed from above, ranging from 0 degrees (mid-saggital, anterior) to 330 degrees, in 30 degrees increments. RMS EMG amplitude data were collected using surface electrodes and normalized to maximal voluntary contractions. Significant changes were observed in the muscle responses due to the interaction of the moment direction and moment magnitude for six of the eight muscles tested. Comparison of the present data with that collected previously in neutral postures indicated: (1) a large increase in the activation levels of the right erector spinae and the left external oblique muscles; and (2) a counter-clockwise shift in the moment direction at which the peak activation of these same muscles occurs. Analysis of the relative activation levels (RALs), constructed from the NEMG data to quantify the cocontraction, indicated that the changes in cocontraction were more robust in response to changes in the bending moment's direction as opposed to changes in bending moment's magnitude.     

Naming two-digit Arabic numerals: Evidence from masked priming studies.

The authors investigated how 2-digit Arabic numerals are named by looking at the effects of masked primes on the naming latencies. Target numerals were named faster when prime and target shared a digit at the same position (e.g., the target 28 primed by 18 and 21). In contrast, naming latencies were slower when prime and target shared 1 or 2 digits at noncorresponding places (e.g., the target 28 primed by 82, 86, or 72). Subsequent experiments showed that these priming effects were situated at the level of the verbal production of the Arabic numerals. The data point to a nonsemantically mediated route from visual input to verbal output in the naming of 2-digit Arabic numerals. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

对型钢厂SWC440万向轴断轴事故的分析与建议

针对一起生产企业和设备生产厂家有争议的SWC440万向轴断轴事故进行了检测分析,通过对断轴进行解体、检测、分析认定,由于“卡钢”和“退钢”造成扭矩或转矩过大形成事故。提出了改进建议。     

Numerical ordering in a chimpanzee (Pan troglodytes): Planning, executing, and monitoring.

Perceptual and cognitive processes underlying the skill of ordering numerals were assessed in a female chimpanzee (Pan troglodytes) with previous experience in computer-assisted numerical competence tasks. The subject was required to order 3 numerals from the range of 0–9 into an ascending series, with occasional probe trials (referred to as switch trials) in which the positions of the 2nd and 3rd numerals were exchanged immediately after the selection of the 1st. On these trials, errors were scored frequently, whereas correct responses to the intermediate numeral became reliably slower. These and other data indicated that the subject had already established, before making the 1st choice, (a) the correct sequence in which she was to select the numerals and (b) the motor sequence leading to a correct answer. These findings show that a 3-unit ordering task is supported in the chimpanzee, much as it is in humans, by planning, executing, and monitoring phases. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modeling the Hinge Moment of Skew-Mounted Tape Spring Folds

Tape springs, defined as thin metallic strips with an initially curved cross section, are an attractive structural solution and hinge mechanism for small satellite deployable structures due to their low mass, low cost, and general simplicity. When mounted at skewed angles to the hinge line, the tapes can be subjected to complex folds involving both bending and twisting of the tape. These folds have been experimentally investigated and theories have been developed to model the resulting opening moment. However, the opening moments of these theories are not equivalent to the opening moment about the hinge line, which is the parameter required in satellite deployment applications. This paper derives a method to determine the hinge moment from the previous theories and compares the theoretical predictions with experimental and finite element results. It uses this model to investigate the predicted hinge moment trends for full deployments of 180°. The model is then applied to a practical spacecraft hinge application.     

Attention gating in short-term visual memory.

Investigated attention shift to a stream of numerals, in rapid serial visual presentation, using 3 graduate students with normal or corrected-to-normal vision. Ss detected a target embedded in a stream of letters presented at the left of fixation and, as quickly as possible, shifted their attention to a stream of numerals at the right of fixation. They attempted to report, in order, the 4 earliest occurring numerals after the target. Numerals appeared at rates of 4.6, 6.9, 9.2, and 13.4 sec. Analyses demonstrated that, for all Ss, targets, and numeral rates, the relative position of numerals in the response sequence showed clustering, disorder, and folding. Reported numerals tended to cluster around a stimulus position 400 msec after the target. Numerals were reported in an apparently haphazard order. The actual order of report resulted from a mixture of correctly ordered numerals with numerals ordered in the direction opposite to their order of presentation. Results are quantitatively described by a strength theory of order and are efficiently predicted by a computational attention gating model (AGM). The AGM may be derived from a more general attention model that assumes that (a) after detection of the target, an attention gate opens briefly to allow numerals to enter a visual short-term memory and (b) subsequent order of report depends on both item strength (how wide the gate was open during the numeral's entry) and on order information (item strength times cumulative strength of prior numerals). (78 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Numeral form as a variable in numeral visibility.

4 experimental sets of numerals, designed to reduce confusions, were compared with a set of the currently most visible numerals under tachistoscopic viewing conditions. 6 of the experimental numerals were shown to be significantly more visible than the current standard. "A hypothesis… is proposed… two important but partially opposed variables in visibility of numerals… [are] boldness of stroke and openness of white space." (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The mental representation of parity and number magnitude.

Nine experiments of timed odd–even judgments examined how parity and number magnitude are accessed from Arabic and verbal numerals. With Arabic numerals, Ss used the rightmost digit to access a store of semantic number knowledge. Verbal numerals went through an additional stage of transcoding to base 10. Magnitude information was automatically accessed from Arabic numerals. Large numbers preferentially elicited a rightward response, and small numbers a leftward response. The Spatial–Numerical Association of Response Codes effect depended only on relative number magnitude and was weaker or absent with letters or verbal numerals. Direction did not vary with handedness or hemispheric dominance but was linked to the direction of writing, as it faded or even reversed in right-to-left writing Iranian Ss. The results supported a modular architecture for number processing, with distinct but interconnected Arabic, verbal, and magnitude representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)