船用蒸汽动力系统使用特性指标分析与评价

船舶动力系统使用特性是其设计论证和使用决策的重要依据,以船用蒸汽动力系统为对象,在对其使用特性进行了分析的基础上,构建了船用蒸汽动力系统使用特性的指标体系,提出了一种面向使用方案和工作参数的使用特性指标近似评价和综合评估方法。     

ADCP的引进及在淮河流量测验中的应用

介绍了ADCP的测流原理和在水文系统使用的优点，通过淮滨站实际使用的例子说明使用ADCP的紧迫性和必要性，提出ADCP使用注意事项和管理规程。     

拖拉机润滑油的选用及注意事项

拖拉机在使用过程中润滑油的选择和正确使用对延缓零件磨损、延长机具使用寿命至关重要,因此,掌握正确使用方法和相关知识十分必要。一、润滑油的选用拖拉机润滑油的选择主要是根据使用条件与内燃机的结构形式和性能,合理正确的选择润滑油的黏度、黏温特性和质量,也就是选择品种和牌号。1)根据使用说明书要求选择。使用说明书上都     

装载机安全使用指南（六）

小心使用千斤顶和提升装置如果要在提升起的装置下工作,一定要使用木块、千斤顶或其他坚硬物体将其支撑固定。在使用千斤顶和提升装置时要确定他们有足够的支撑力。警告：禁止使用混凝土块支撑,因为混凝土块在大负载下可能会崩塌。确保提升装置和千斤顶方便维修。禁止使用有裂痕、弯曲扭曲的千斤顶;禁止使用磨损、扭曲或收缩的电缆;禁止使用弯曲或歪的钩子。     

螺纹联接在不同场合的正确使用

在构成机械设备的要素零件中，使用最广最多的是螺栓和螺母，因此使用目的和使用环境也是多种多样。     

微耕机安全使用9要点

熟练掌握操作技能。使用微耕机前，必须熟读使用说明书，牢记“使用须知”和“安全规则”，必须有大于4h的操作技能训练经历才可上岗作业。决不允许儿童和没有阅读说明书的人操作使用。     

冬夏拖拉机使用与维护

夏季温度高、冬季温度低,期间拖拉机使用不注意维护和保养,必将影响其寿命,降低使用安全性和稳定性。就冬夏两季特殊性,就科学合理使用拖拉机进行系统分析论述,为今后提升拖拉机使用寿命,增加拖拉机使用可靠性,提供参考和借鉴。     

探析汽车使用和维修对汽车技术状况的影响

作为重要交通工具,汽车长时间使用后会常出现性能衰减问题,想要使汽车保持良好技术状况还要加强使用和维修管理。基于这种认识,本文从汽车使用和维修两方面分析了汽车技术状况受到的影响,从而为汽车使用和维护提供相应参考意见。     

玉米田除草剂的选择与使用

使用除草剂省时、省力,节约成本,提高收益,但同时也易污染环境,造成药害。正确合理使用除草剂是玉米取得高产稳产的关键因素,了解其作用机理和使用方法是选择和使用好除草剂的关键。     

谈液压系统使用管理的系统化

本文针对液压系统使用管理中存在的问题，应用管理工程学原理提出液压系统的使用管理体系，提出液压系统使用维修改造过程系统化的设想，强调了动态管理的意义，提出了液压系统使用管理者提高专业素质的训练内容，阐述了液压系统使用管理系统化的任务和意义，对提高液压系统的使用水平和发挥液压设备最佳经济效益具有一定参考价值。     

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.     

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。     

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....     

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.