浅谈出口俄罗斯起重机的设计注意事项

通过对俄罗斯GOST起重机设计规范及PB10-382-00起重机构造及安全操作规则与我国GB/T3811-2008起重机设计规范及GB/T14405-1993通用桥式起重机标准的比较,提出出口俄罗斯起重机设备时,设计人员应该注意的事项.     

铁磁性钢丝绳电磁检测仪试验台研制

国内尚未有满足标准GB/T21837-2008《铁磁性钢丝绳电磁检测方法》中要求的铁磁性钢丝绳电磁检测仪试验台，阐述了研制试验台的意义和作用。针对GB/T21837-2008和GB/T26832-2011标准要求研制了专用于铁磁性钢丝绳检测仪的试验台，并制备了具有局部损伤LF和金属横截面积损失LMA的钢丝绳缺陷样绳用于钢丝绳探伤仪检验和校准，为钢丝绳探伤择优提供科学的测试平台和判断依据。     

简析无损检测两项新标准

JB/T 6065-2004《无损检测磁粉检测用试片》(以下简称JB新标准)及GB/T 5097-2005《无损检测渗透检测和磁粉检测观察条件》(以下简称GB新标准),分别代替JB/T 6056-1992《磁粉探伤用标准试片》(以下简称JB旧标准)和GB/T 5097-1985《黑光源的间接评定方法》(以下简称GB旧标准)两项标准.     

GB/T 4728《电气简图用图形符号》系列标准贯标方法研究(续十三)

10 关于GB/T 20295-2006 《GB/T 4728.12和GB/T 4728.13标准的应用》 (1)标准制修订情况 GB/T 20295-2006等同采用IEC TR61734:1997 《IEC 60617-12和IEC 60617-13标准的应用》.IEC在相隔九年后发布了IEC TR 61734:2006《二进制逻辑和类似原理的符号应用》,但两者内容和层次完全相同,后者改用数据库符号表述方式.目前我国国家标准正在针对IEC TR 61734:2006进行GB/T20295-2006的修订工作.GB/T 20295-2006与GB/T4728.12-2008《电气简图用图形符号 第12部分:二进制逻辑件》和GB/T 4728.13-2008《电气简图用图形符号第13部分:模拟件》内容比较见表35.     

柴油机机油的检测及润滑周期的确定

我集团对工程机械柴油机用油均实行250h更换周期。为节约成本,我们对柴油机机油做过专项检测,目的是确定科学的换油周期。检测工作由合肥澳培林石油产品检测咨询有限公司,根据GB/1265-88、GB/T1995-88、GB8030-87和SH/T0251等相关标准进行检测。抽     

闭口包装钢桶生产过程检测技术分析与研究

根据GB/T325-2000标准要求,对闭口包装钢桶生产过程检测项目进行技术分析和研究,提出切实可行的检测方法。参照GB/T325-2000标准要求,结合生产过程,应用比对法、测量法、计算法、试验法及源头控制等,对生产实践中的检测方法进行提炼。通过比对、测量、计算、试验以及源头控制等方法,可逐项对GB/T 325-2000标准提出的要求或指标进行检测或控制。利用技术分析办法,对生产过程中的产品质量进行监控,可以防止不合格品的生产、流转和放行出生产企业。     

《铸造行业准入条件》涉及标准及主要文件概览

1标准(1)GB/T19001—2008《质量管理体系要求》针对:产品质量《铸造行业准入条件》(以下简称"《条件》")引文:铸造企业应按照GB/T19001—2008标准(或ISO/TS16949—2009《质量管理体系》标准)建立质量管理体系,设有独立质量管理及监测部门,配有专职质量监测人员,有健全的质量管理制度。     

GB/T 8464铁制、铜制和不锈钢制螺纹连接阀门新旧标准解析

新修订的国家标准GB/T 8464-2023《铁制、铜制和不锈钢制螺纹连接阀门》已于2023年3月17日发布,并于2023年10月1日实施。本文从适用范围、零件材料、技术要求、试验方法、检验规则等多方面对新版标准与旧版标准GB/T 8464-2008《铁制和铜制螺纹连接阀门》进行比对和分析。主要对新版标准新增加的“不锈钢制螺纹连接阀门相关技术要求”进行介绍,重点对修订前后变化较大的“球阀球体表面防腐蚀性能要求及其加严的试验方法、金属密封止回阀密封性能等级提高、涉及生活饮用水管道上的阀门卫生性能提升及其金属污染物析出限量和相应的检测方法”等内容开展解读,为相关企业的研发、制造、检测人员提供参考,促进相关从业者更系统、全面、准确地理解和应用新版标准。     

国家标准《工业阀门压力试验》(GB/T13927-2008)的分析

对GB/T13927-2008《工业阀门压力试验》进行了讨论和分析,对标准中的相关规定提出了修订建议。     

电梯T型导轨国标和原行标几何公差要求浅析

2009年6月1日起实施的GB/T22562—2008《电梯T型导轨》与被替代标准JG/T5072.1—1996《电梯T型导轨》相比,从表述方式到实质内容都有较大差异。本文以高质量导轨为例,详细分析了两标准有关形位公差的要求,并给出定量分析比较,同时揭示出以翘曲高度表示导轨扭曲时,和扭转角度间的对应关系。分析结果表明,原行标的形位公差要求比较抽象,而国标则更为合理、明确,对检测要求更高,两者的转换和导轨具体型号有关。分析结果对标准的理解与导轨的检测有一定的指导意义。     

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.     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.