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。     

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。     

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     

关于电子衡器安装使用维护的技术探讨——浅谈电子衡器使用应了解的基本知识

电子衡器,是一种具有法制性、技术性的计量工具。电子衡器,是当今“万物互联”时代“物联网”的重要组成部分。电子衡器的安装调试、操作使用与维护管理,是电子衡器稳定运行、称量准确的保证环节。电子衡器制造,应高质量安装、调试、校准;电子衡器用户应学习掌握电子衡器使用的基础知识。使用现场条件、使用环境及使用操作维护,应满足电子衡器的技术要求。电子衡器的使用效果,是技术制造、操作使用与法制管理共同创造的应用成果。     

气象用水银气压表的使用及注意事项

文章在介绍动槽式水银气压表工作原理的基础上,重点分析了水银气压表的正确使用及使用过程中应注意的事项,只有正确地使用,才能减少水银气压表的仪器误差和使用误差.     

钳形电流表使用时的注意事项

正钳形电流表是一种常用的测量仪表,被广泛的应用于多个行业中。钳形电流表具有测量精准、稳定性好、使用灵活等多种的优点。我们在使用钳形电流表的时候不仅要对于它的使用步骤有一定的了解,对于他使用的注意事项也是不可忽视的。钳形电流表是一种常用的测量仪表,被广泛的应用于多个行业中。钳形电流表具有测量精准、稳定性好、使用灵活等多种的优点。我们在使用钳形电流表的时候不仅要对于它的使用步骤有一定的了解,对于他使用的注意事项     

电子汽车衡在使用中应注意的问题

本文主要介绍了电子汽车衡在使用前、使用中、使用后分别应注意的问题。     

大学教师课堂幽默使用频率与效果的关系初探

本文主要目的在于初步编制大学教师课堂幽默使用频率量表,同时检查大学教师课堂幽默使用频率与使用效果之间的关系。访谈和问卷调查结果表明,编制的大学教师课堂幽默使用频率量表具有较好的信度和效度,可作为教学幽默研究的一种实证研究工具;大学教师课堂幽默使用频率与效果呈显著正相关,大学教师课堂幽默使用具有积极的作用。     

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。     

春季农机安全作业注意事项

1使用前清理、润滑、调整 应按使用说明书要求,进行使用前的清理、润滑和调整,确保机具以良好的技术状态投入作业;对动力机械润滑系统的保养,除按规定的标准使用润滑油外,还要严格遵守润滑系统保养周期和使用规范,定期清洗润滑系统,定期更换过滤部件,减小机件磨损。     

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...     

On the Relation of Load to Average Gap in the Contact Between Surfaces with Longitudinal Roughness

A computer simulation model for the contact between longitudinally-oriented rough surfaces has been formulated. This model closely duplicates the actual surf ace contact deformation behavior by taking into account the elastic interactions between the asperities. There were no assumptions made about the shapes, or any deformation behavior of the asperities, except for their obeying the laws of elasticity. The plastic deformations on the high asperity peaks were taken into account by setting a ceiling on their contact pressures at the material hardness value. The simulations used real surface profiles which were digitized from unworn circumferentially ground steel surfaces. Each pair of these profiles was mathematically combined to form an equivalent rough profile pressing against an infinitely rigid flat and having the appropriately adjusted elastic modulus. A total of 28 different pairs of profiles were used in the simulations. Each contacting pair was subjected to 30 different load levels and the local contact pressures and deformations were calculated. The contact simulations yielded some important mathematical relationships between parameters, such as the real area of contact, average gap, and average asperity load through statistical curve fitting. Two analytical functions were generated to relate the average load to average gap and the real area of contact to load.     

三绕组变压器的双绕组等效建模及在Matpower中的应用

针对实际电网存在着大量的三绕组变压器,但国际上一些著名商业软件,如BPA仿真软件、Matpower这一权威潮流计算开源软件,均只提供双绕组变压器模型,限制了其在具有三绕组变压器的电力系统中的应用的问题,潮流计算是自主开发的电力系统各种应用软件的核心模块,因此依托国际权威开源程序进行二次开发,是一种较好的选择。对Matpower要求的数据格式进行了归纳,对变压器的一般的等值电路及带理想变压器的等值电路和带标幺值的等值电路进行了分析研究,提出了三绕组变压器转换为双绕组等效模型的建模方法,使得原先只适应双绕组变压器的潮流计算软件可以适用于三绕组变压器电网的潮流计算;最后以Matpower软件为例进行了案例计算,并用PSASP仿真软件进行对比验证。研究结果证明,所提出的建模方法是有效的。     

Quantum Cooperative Robotics and Autonomy

The intersection of Quantum Technologies and Robotics Autonomy is explored in the present paper.The two areas are brought together in establishing an interdisci...     

电站锅炉模糊风险评价方法研究与应用

针对电站锅炉风险等级评价问题,将模糊综合评价技术应用到电站锅炉风险等级评价中。开展了电站锅炉失效影响因素及模糊评价因素的重要程度分析,建立了一套科学合理适于在线评价的电站锅炉风险评价体系,提出了模糊综合评价技术与改进的模糊层次分析法相结合的模糊风险评价方法,利用改进的模糊层次分析法计算了指标体系中各层指标权重。对某一台电站锅炉的实际运行工况影响子因素进行了模糊风险评价,采用模糊合成算子进行模糊综合运算得到电了站锅炉运行工况影响子因素的评价向量。研究结果表明:电站锅炉的运行工况影响子因素的风险评价等级为第6级,失效可能性等级为小,该电站锅炉运行工况良好。     

考虑进油孔有限长滑动轴承油膜力的近似解析解

针对具有进油孔的有限长滑动轴承油膜力求解问题,采用变分原理和分离变量法,求得了有限长滑动轴承油膜压力分布的近似解析表达式。将油膜压力分布的近似解析表达式在油膜存在区域上进行积分,即得到了油膜力。将提出的计算有限长滑动轴承油膜力方法与无限长轴承模型、有限元方法的计算结果进行了比较,发现了提出的方法与有限元方法的计算结果很接近。最后,研究了进油孔位置和进油压力对油膜存在区域、油膜力等的影响,研究结果表明进油孔位置和进油压力对油膜存在区域和油膜力有较大的影响。     

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.     

交通荷载作用下桥梁结构参数识别方法

应用动力节点加载法,将作用在桥梁上的交通荷载转化为等效节点荷载,再用两步构造法识别结构物理参数.第1步,用Newmark-β方法变换结构运动方程,并用结构的加速度响应求得变换空间内的位移、速度和加速度响应;第2步,基于最小二乘原理,构造出变换空间内求解结构参数的递推式,进行结构物理参数识别.数值模拟结果表明,在交通荷载作用下,该方法能够快速、准确地进行桥梁结构参数识别.     

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...