回转窑滚圈应力的测试方法研究

针对现阶段滚圈的强度分析主要依据简化模型下的有限元分析,导致不能真实反应滚圈的应力情况,且误差较大的问题.提出了通过用电测法来实测滚圈的真实应力,并了解滚圈的应力分布特性,这对于指导设计部门改进滚圈的设计,正确预测滚圈的寿命,具有重要的工程意义.     

SubLVDS驱动电路的设计

SubLVDS是一种超低压摆幅的差分信号技术,与传统的低摆幅差与信号技术相比,它具有更高的比特率、更低的功耗、更好的噪声性能和更稳定的可靠性.分析了SubLVDS的技术原理和优势,并给出了SubLVDS高速驱动电路的设计,其中采用MOS电容组成的高速降幅电路,利用负反馈和米勒补偿稳定共模点,采用SMIC 0.18 μm工艺,1.8 V的供电,最后实现摆幅为150 mV的、速度为1 Gbps、PSRR大于60 db的驱动电路.     

船舶ERP选型:集成性是关键

当前,信息化已经渗透到世界船舶工业的设计、生产、管理、服务等方方面面,其应用的深度与广度决定了行业综合水平的高低,成为大至一个国家的船舶工业、小至一个船舶企业能否在市场中生存和发展的关键.当造船业已经普遍意识到,以"信息化推动造船现代化"是中国造船工业追赶国际先进水平的最后机遇时,造船业的生存发展与IT厂商的策略几乎在同一时间不谋而合,在造船业竞争的搏奕中厂商的相助少不了.     

硬盘In-Drive 伺服刻写的设计及实现

硬盘的伺服刻写是整个硬盘产生的核心,其中伺服刻写中所产生的RRO是影响硬盘伺服质量的重要标志,并且RRO的大小决定着硬盘的功耗.采用传统的Media伺服刻写技术会产生很大的RRO,影响伺服信号的质量;而采用In-Drive伺服刻写技术可以避免传统伺服刻写中存在的问题.本文给出了In-Drive伺服刻写技术的详细设计方案和实现过程,对比Media伺服刻写方法,采用该策略实现的In-Drive伺服刻写,可降低伺服定位信号的波动及伺服位置的偏差,而且基准时钟写闭一般不超过4次.     

电火花加工技术的高效化研究进展

随着电火花加工技术的不断发展与成熟,进一步提高其加工速度成为人们不断关注的焦点.在纵观近年来电火花加工技术的发展现状及趋势的基础上,从电火花加工的基础理论研究、新型加工工艺及方法的采用、控制系统的自动化及智能化程度的不断提高、设备结构及其它辅助部件的改进等四个方面介绍了高效电火花加工技术的研究进展.     

建立科学的信息编码体系是信息化建设取得成功的重要保证

随着计算机网络技术的发展,信息化建设日益受到企业的重视,近年来很多企业加大了在这方面的投入,期望借助先进的信息化手段在生产经营管理上取得更好的效果.但是,从目前的情况来看,我国企业信息化建设的效果并不理想,很多企业并未从信息化建设中获得预期的回报.     

脱脂机组卷取张力自动优化设定技术的研究

经过大量的现场试验与理论研究,针对脱脂机组的卷取设备与工艺特点,充分考虑到后步工序的粘酷与松卷问题,在首次提出粘结与松卷综合控制目标函数的基础上,建立了一套完整的脱脂机组卷取张力自动优化设定技术,并将其应用到宝钢1220脱脂机组的生产实践中,取得了良好的使用效果,大大降低了粘结与松卷的发生率,创造了很大的经济效益,具有进一步推广应用的价值.     

数控设备操作失误及预防措施

随着数控的技术飞速发展和我国对数控技术投入的不断增加,拥有数控设备的企业越来越多,在数控机床的操作过程中由于操作不当而引起的事故不在少数,有的时候还会造成不可估量的损失.这样就要求数控设备的操作人员对常见操作失误有必要的了解.本文将和大家一起探讨数控机床操作常见问题及预防处理方法.     

高职院校机械实训中心管理探讨

就高职院校的机械实训中心的设备及人身安全、物流、工器具的使用、消耗材料的使用、教学管理等方面作了全面的阐述,结合实际总结了不同于生产企业的人流及物流的管理办法,并对一些有待于改善的存在问题提出了建议.     

电池的环保主义

现今社会,健康、环保已经成为全球的主旋律,人们渴望干净的地球,渴望健康的生命,渴望环保绿色的家园.腕表的设计、研发者们以及相关部门为了这个目标一直在不懈地努力着,为这个主题乐章奏出了美妙的和声.     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

INTEGRAL EQUATION METHOD＇S APPLICATION IN HOLE-EDGE STRESS OF COMPOSITE MATERIAL PLATE WITH DIFFERENT SHAPED HOLES

The strength of composite plate with different hole-shapes is always one of the most important but complicated issues in the application of the composite material. The holes will lead to mutations and discontinuity to the structure. So the hole-edge stress concentration is always a serious phenomenon. And the phenomenon makes the structure strength decrease very quickly to form dangerous weak points. Most partial damage begins from these weak points. According to the complex variable functions theory, the accurate boundary condition of composite plate with different hole-shapes is founded by conformal mapping method to settle the boundary condition problem of complex hole-shapes. Composite plate with commonly hole-shapes in engineering is studied by several complex variable stress fimction. The boundary integral equations are founded based on exact boundary conditions. Then the exact hole-edge stress analytic solution of composite plate with rectangle holes and wing manholes is resolved. Both of offset axis loadings and its influences on the stress concentration coefficient of the hole-edge are discussed. And comparisons of different loads along various offset axis on the hole-edge stress distribution of orthotropic plate with rectangle hole or wing manhole are made. It can be concluded that hole-edge with continuous variable curvatures might help to decrease the stress concentration coefficient; and smaller angle of outer load and fiber can decrease the stress peak value.     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity ar...     

End-to-End Multiview Gesture Recognition for Autonomous Car Parking System

The use of hand gestures can be the most intuitive human-machine interaction medium.The early approaches for hand gesture recognition used device-based methods....     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

The laboratory simulation of abrasive wear

Abrasive wear has long been recognised as one of the most potentially serious tribological problems facing the operators of many types of plant and machinery; several industrial surveys have indicated that wear by abrasion can be responsible for more than 50% of unscheduled machine and plant stoppages. Locating the operating point of a tribological contact in an appropriate operational ‚map’︁ can provide a useful guide to the likely nature and origins of the surface degradation experienced in use, though care must be exercised in choosing the most suitable parameters for the axes of the plot. Laboratory testing of materials and simulations of machine contacts are carried out for a number of purposes; at one level for the very practical aims of ranking candidate materials or surface hardening treatments in order of their wear resistance, or in an attempt to predict wear lives under field conditions. More fundamentally, tests may be aimed at elucidating the essential physical mechanisms of surface damage and loss, with the longer term aim of building an analytical and predictive model of the wear process itself. In many cases, component surface damage is brought about by the ingress of hard, particulate matter into machine bearing or sealing clearances. These may be running dry although, more usually, a lubricant or service fluid is present at the interface. A number of standardised wear test geometries and procedures have been established for both two- and three-body wear situations, and these are briefly described. Although abrasive wear is often modelled as following an ‚Archard’︁ equation (i.e. a linear increase in material loss with both load and time, and an inverse dependence on specimen hardness) both industrial experience and laboratory tests of particularly lubricated contacts show that this is not always the case: increasing the hardness differential in an abrasively contaminated lubricated pair may not always reduce the rate of damage to the harder surface.     

ANGULAR DISTORTION ALLOWABLE VALUE AND ASSESS METHOD OF WELD ON COKE TOWER

A graph as the new engineering method for estimate the safety of bulging deformation of coke tower is proposed. Through stresses analysis of circumferential weld of coke tower and comparing the stresses produced by pressure with heat stress of steady state, residual stress, bending stress produced by both itself weight and wind loads, it showed that the stresses produced by pressure on the angle distortion are the main factor of equivalent stress of the combined stress. After comparing four kinds of stress controlling conditions, the relation to stress with depth of angular distortion, grade of curvature of angular distortion and half of region of angular distortion has been inferred. Graph of deformation allowable value of coke tower for different condition by angular distortion and half of region of angular distortion has been plotted. The five steps for its engineering use have been explained. The lighter the grade of curvature is, the larger of bulge allowance, may be, and the bigger of depth of angular distortion may pose too. For the coke tower with a popular structure of Dg 5 400 mm×28 mm, the result by graph is nearly more than the result of two formulas formed by other research, the error is less than 7.0%. But, the graph can be easily applied to different size of angular distortion.