检索结果-南通市图书馆

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

建筑企业造价管理信息化的优化策略研究

工程造价管理 2024年第4期35卷 67-74页

作者：何立冬北京戴纳实验科技有限公司北京100025

在互联网信息化科技的推进下,越来越多的建设企业逐步开始将造价管理工作与信息化技术相结合,希望通过信息化技术将造价管理做到精细化,从而提高企业的利润率。调查发现,建筑企业在造价信息化的初期存在数据混乱、流程制度不完善、信息... 详细信息

在互联网信息化科技的推进下,越来越多的建设企业逐步开始将造价管理工作与信息化技术相结合,希望通过信息化技术将造价管理做到精细化,从而提高企业的利润率。调查发现,建筑企业在造价信息化的初期存在数据混乱、流程制度不完善、信息化系统操作流程过于机械化、缺乏合理的执行过程管理等问题。文章基于常见问题的分析,提出优化策略:建筑企业使用信息化技术对造价进行管理,应先制定完善的管理制度和强化人机互动的友好操作方式,规范基础数据库的编制规则和维护方式来加强对基础数据库的整理,根据企业信息化系统的操作流程和方式,完善对造价信息化的管理,运用信息化技术逐步提高造价管理工作的效率和精细化的管理目标。

关键词：造价信息化造价管理物料编码人机友好

基于ERP数据库的工程成本管理优化策略研究

在线全文

学校读者我要写书评

暂无评论

工程造价管理 2024年第1期35卷 30-36页

作者：何立冬北京戴纳实验科技有限公司北京100025

随着互联网信息化的逐步发展,网络智能化对当前各行业的发展带来了不小的冲击,处于传统行业的建设工程企业受到生产管理方式变革的重大影响。在“放管服”政策的推动下,建设工程企业的成本管理工作需要进行精细化和时效性提升的优化升... 详细信息

随着互联网信息化的逐步发展,网络智能化对当前各行业的发展带来了不小的冲击,处于传统行业的建设工程企业受到生产管理方式变革的重大影响。在“放管服”政策的推动下,建设工程企业的成本管理工作需要进行精细化和时效性提升的优化升级。文章基于目前互联网大数据时代背景下对工程企业成本管理工作的影响分析,结合对目前部分企业运用ERP数据库遇到的常见问题进行研究和思考,提出优化策略:工程企业的成本管理工作应借助大数据科技发展带来的技术推动,根据企业经营特性建立内部的物料编码体系、标准化的成本数据库,在企业的管理工作中促进内部的数据协调一体化,运用大数据分析的模式对成本管理工作进行优化提升,逐步完善企业成本数据库智能化管理机制,提高企业经营利润率。

关键词：成本管理 ERP数据库物料编码人机友好数据协同

在线全文

学校读者我要写书评

暂无评论

拖链系统的优点与局限性评估及改进策略研究

中国高新科技 2024年第7期 83-85页

作者：贺立东上海振华重工(集团)股份有限公司长兴分公司上海201913

码头岸桥上的拖链系统是现代物流领域中常用的设备,在输送和保护电力、信号和控制电缆方面起着重要作用。文章旨在评估拖链系统的优点和局限性,并提出改进策略。对拖链系统的优点进行了分析,对拖链系统的局限性进行了讨论,接着,对优点... 详细信息

码头岸桥上的拖链系统是现代物流领域中常用的设备,在输送和保护电力、信号和控制电缆方面起着重要作用。文章旨在评估拖链系统的优点和局限性,并提出改进策略。对拖链系统的优点进行了分析,对拖链系统的局限性进行了讨论,接着,对优点和局限性进行了评估和比较,以确定改进的方向。最后,提出了结构改进、润滑与降噪策略、智能化与自适应控制及可靠性与维护策略等改进策略。

关键词：码头岸桥拖链系统优点局限性改进策略

在线全文

学校读者我要写书评

暂无评论

岸桥小车轨道排装系统设计与性能优化研究

中国高新科技 2024年第1期 82-83,86页

作者：贺立东上海振华重工(集团)股份有限公司长兴分公司上海201913

文章研究了岸桥小车轨道排装系统的设计与性能优化,旨在提高港口装卸效率。通过系统性能分析,优化运动控制算法和货物排列,实现高效运作。研究中建立了动力学模型,评估了系统的运行稳定性,探讨了智能化技术和设备升级的应用。然而,随着... 详细信息

文章研究了岸桥小车轨道排装系统的设计与性能优化,旨在提高港口装卸效率。通过系统性能分析,优化运动控制算法和货物排列,实现高效运作。研究中建立了动力学模型,评估了系统的运行稳定性,探讨了智能化技术和设备升级的应用。然而,随着物流需求的多样化和智能化趋势,进一步研究系统的灵活性和环境可持续性,将是未来的关键方向。

关键词：岸桥小车轨道排装系统设计性能优化运行稳定性效率吞吐量

Effects of Four Types of Pre-swirls on the Leakage, Flow Field, and Fluid-Induced Force of the Rotary Straight-through Labyrinth Gas Seal

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Mechanical Engineering 2019年第3期32卷 119-133页

作者： Qingfeng Wang lidong he Beijing Key Laboratory of health Monitoring and Self-Recovery for High-End Mechanical Equipment Beijing University of Chemical TechnologyBeijing 100029China College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China

The labyrinth seal in turbomachinery is a key element that restricts leakage flow among rotor-stator clearances from high-pressure regions to low-pressure regions. The fluid-induced forces on the rotor from seals during machine operation must be accurately quantified to predict their dynamic behavior effectively. To understand the fluid-induced force characteristics of the labyrinth seal more fully, the effects of four types of pre-swirls on the leakage, flow field, and fluid-induced force of a rotary straight-through labyrinth gas seal (RSTLGS) were numerically investigated using the proposed steady computational fluid dynamics (CFD) method based on the three-dimensional models of the RSTLGS. The leakage, flow field, and fluid-induced force of the RSTLGS for six axial pre-swirl velocities, four radial preswirl angles, four circumferential positive pre-swirl angles, and four circumferential negative pre-swirl angles were computed under the same geometrical parameters and operational conditions. Mesh analysis ensures the accuracy of the present steady CFD method. The numerical results show that the four types of pre-swirls influence the leakage, flow field, and fluid-induced force of the RSTLGS. The axial pre-swirl velocity remarkably inhibits the fluid-induced force, and the circumferential positive pre-swirl angle and circumferential negative pre-swirl angle remarkably promote the fluid-induced force. The effects of the radial pre-swirl angle on the fluid-induced force are complicated, and the pressure forces and viscous forces show the maximum or minimum values at a specific radial pre-swirl angle. The pre-swirl has a negligible impact on the leakage. The four types of pre-swirls affect the leakage, flow field, and fluidinduced force of the RSTLGS to varying degrees. The pre-swirl is the influence factor affecting the leakage, flow field, and fluid-induced force of the RSTLGS. The conclusions will help to understand the fluid-induced force of labyrinth seals more

关键词： Rotary straight-through labyrinth gas seal Pre-swirl Leakage Flow field Fluid-induced force

Effect of integral squeeze film damper on vibration and noise of spur gear with center-distance error

在线全文

学校读者我要写书评

暂无评论

High Technology Letters 2022年第4期28卷 418-424页

作者： DONG Huaiyu he lidong JIA Xingyun Engineering Research Center of Chemical Technology Safety Ministry of Education Beijing 100029P.R.China

When the actual installation center distance between a pair of spur gears is greater than the theoretical center distance,backlash increases,leading to increased vibration and *** structural parameters of an integral squeeze film damper(ISFD)were designed with the stiffness of rigid support as reference to investigate the effect of an ISFD on the dynamic characteristics of a spur gear transmission system with center-distance installation error.A spur gear test bench with center distance-error was built to investigate the vibration and noise reduction characteristics of *** experimental results indicate that,compared with a rigid support,the ISFD can reduce vibration by approximately 40%and noise by approximately 5 d *** can effectively absorb the impact energy caused by an increase of in backlash,which is conducive to the stable operation of the spur gear transmission system.

关键词： dynamic backlash integral squeeze film damper(ISFD) spur gear transmission system vibration and noise control

Effect and sensitivity analysis of the rotational speed on the fluid-induced force characteristics of the straight-through labyrinth gas seal

在线全文

学校读者我要写书评

暂无评论

High Technology Letters 2018年第1期24卷 62-74页

作者：王庆峰 he lidong Beijing Key Laboratory of health Monitoring and Self-Recovery for High-End Mechanical Equipment Beijing University of Chemical Technology Beijing 100029 P. R. China College of Mechanical and Electrical Engineering Beijing University of Chemical Technology Beijing 100029 P. R. China

The effects of the rotational speed on the fluid-induced force characteristics of a straight-through labyrinth gas seal( STLGS) are numerically investigated using the steady computational fluid dynamics( CFD) method based on a three-dimensional model of the STLGS. The fluid-induced force characteristics of the STLGS for five rotational speeds at a pressure drop of △P = 5000 Pa with and without eccentricity are computed. The grid density analysis ensures the accuracy of the present steady-CFD method. The effect and sensitivity analysis show that the changes in rotational speed affect the pressure forces,viscous forces and total pressure distributions on the rotor surface,velocity streamlines,leakage flow rates,and maximum flow velocities. The results indicate that the rotational speed inhibits the pressure forces,leakage flow rates and maximum flow velocities and promotes the viscous forces and total pressure on the rotor surface.

关键词： labyrinth seal fluid-induced force rotational speed computational fluid dynam-ics (CFD) sensitivity analysis

Event-based Measurement Scheduling for Linear Quadratic Gaussian Control

在线全文

学校读者我要写书评

暂无评论

Event-based Measurement Scheduling for Linear Quadratic Gaus...

Research on suppress vibration of rotor misalignment with shear viscous damper

第36届中国控制会议

作者： lidong he Yifei Qi Yun Zou School of Automation Nanjing University of Science and Technology State Key Laboratory of Industrial Control Technology and College of Control Science and EngineeringZhejiang University

ISBN: (纸本)9781538629185

This paper investigates measurement scheduling for linear quadratic Gaussian（LQG） *** measurement collected via the local sensor is sent over the bandwidth-limited channel to the remote controller for regulating the system *** event-based scheme is designed at the local scheduler to smartly choose the time for sending the data,so as to reduce the uncertainty of system state at the controller side,as well as to reduce the communication *** to the fixed event-triggered rule,we show that the control law and the estimation algorithm can be separately *** that basis and by virtue of the introduced generalized closed skew normal distribution,a minimum mean-squared error estimation algorithm is proposed,which promotes the existing scheduling scheme to any communication rate.

关键词： Event-based scheduling separately design LQG control optimal estimation

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

High Technology Letters 2015年第2期21卷 239-243页

作者：黄秀金 he lidong Wang Cai Safety Engineering Research Center of the Ministry of Education Beijing University of Chemical Technology

A new type of shear viscous damper for rotating machinery is designed. The new damper with good stability and reliability can inhibit all kinds of frequency multiplication vibration caused by misalignment in the condition of nonstop machine. It analyzes and discusses the use of the shear viscous damper for misalignment vibration response inhibition with a finite element method, and experi ments are extensively carried out with a laboratory test rig. Both the simulation and experimental re suits basically agree well in that, the damper can effectively control the misalignment vibration of the rotor system and improves the stability of the plitude of one time running speed component bration has been basically eliminated. entire rotor system. Experimental results show the am decreases by 30% , and the two time running speed vibration has been basically eliminated.

关键词： shear viscous damper misalignment rotor system vibration control