直流电能计量标准装置测量结果的不确定度评定

高准确度直流电能计量标准装置用于检定或校准下一级的直流标准电能表,构成直流电能量值溯源体系中的重要一环。本文分析了高准确度直流电能计量标准装置的测量结果的不确定度,列出了测量不确定度分量的主要来源：电压测量、电流测量、电能脉冲测量,用A类评定方法和B类评定方法进行了不确定度评定。     

规范电能计量标准量值传递工作浅析

电能计量标准量值传递是电力企业计量工作的重要组成部分,是保证量值溯源、精确量值传递,加强计量标准管理,提高工作效率、工作质量及工作准确性的基础。从实际工作出发,介绍了如何建立健全计量标准体系,阐述了如何推进标准装置的管理和维护工作。规范电能计量标准量传递工作,保证了计量标准量值传递的准确性、可靠性和一致性,为更好地实现服务秦皇岛地区经济建设的目标奠定了良好的基础。     

二等量块标准装置示值误差的不确定度

根据国家计量技术规范JJFl059-1999及JJFl033-2001中的有关“不确定度评定与表示”的最新要求,结合本单位的实际情况,给出长度计量的最高标准器二等量块标准装置示值误差的不确定度评定,该评定结果满足相关计量技术规范的要求,保证了长度计量标准的量值传递与溯源的有效可靠,能够满足计量标准复查的需要,并与国际通行做法接轨。     

微波功率计量保证方案研究

计量保证方案(MAP)是一种量值传递与溯源的新方法,通过期间核查,采用数理统计方法对测量过程进行控制,实现闭环量值传递.本文主要研究微波功率计量保证方案,梳理微波功率计量保证方案的实施步骤,实现微波功率量值传递与溯源.     

一种直流数字化电能表的量值溯源方案

直流数字化电能表在电能计量中应用日益广泛,但缺乏专门针对直流数字化电能表量值溯源方案的研究。针对我国缺乏对直流数字电能表量值溯源方案的研究现状,以及现有的交流数字电能表量值溯源方案中存在标准电能计算准确度受采样频率限制、量传误差环节多等问题,提出了一种基于直流数字化标准功率源的直流数字电能表量值溯源方案。该方案在交流数字电能表量值溯源方案的基础上,利用标准数字功率源内置DSP的数字波形拟合与抽取,替代交流溯源方案中的A/D转换;利用DSP高频数字采样积分,替代交流溯源方案中的标准数字电能表。简化了交流数字表的溯源方案,减少量传误差,提高了直流标准电能计算精度,实现了直流数字化电能表的量值溯源,是直流数字化电能表量值溯源的一种新方案。     

建立测力仪标准装置的方案探讨

依据计量标准考核的要求,通过对计量标准的工作原理,不确定度的评定及进行重复性、稳定性指标和不确定度的验证考核,建立符合量值传递规则的测力仪计量标准装置。     

真空标准装置建标分析探讨

依据计量标准考核的要求,通过对计量标准的工作原理,不确定度的评定及进行重复性、稳定性指标和不确定度的验证考核,建立真空标准装置符合量值传递的标准器组     

扭矩仪标准装置建标方案探讨

依据计量标准考核的要求,通过对计量标准的工作原理,不确定度的评定及进行重复性、稳定性指标和不确定度的验证考核,建立扭矩仪标准装置符合量值传递的标准器组     

基于原子力显微术的5 nm台阶高度标准物质溯源与定值技术研究

纳米台阶高度标准物质是一种具有特定量值的物理标准物质,主要用于量值传递以及相关纳米测量仪器的校准。在获批国家标准物质之前,其量值的准确性、稳定性等计量特性必须经过严格的计量测试,才能得到行政许可部门的认可。针对5 nm这一较小量值的纳米台阶高度标准物质的定值方法进行了详细介绍,由中国计量科学研究院自主研制建立的毫米级纳米几何结构计量标准装置采用单一原级的定值方式进行严格定值,采用方差分析法进行均匀性检验,保障了台阶高度量值的溯源性与准确性,定值结果为:h=(5.8±1.0) nm,k=2,并在12个月的时间内进行稳定性监测,最终实现了国家一级标准物质的成功申报。     

电感测微仪计量建标方案分析

依据计量标准考核的要求,通过对计量标准的工作原理,不确定度的评定及进行重复性、稳定性指标和不确定度的验证考核,建立电感测微仪校准装置符合量值传递的标准器组     

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.