Dynamic Response of Foundations during Startup of High-Frequency Tunnel Equipment

The specialized equipment utilized in long-line tunnel engineering is evolving towards large-scale,multifunctional,and complex orientations.The vibration caused by the high-frequency units during regular operation is supported by the foundation of the units,and the magnitude of vibration and the operating frequency fluctuate in different engineering contexts,leading to variations in the dynamic response of the foundation.The high-frequency units yield significantly diverse outcomes under different startup conditions and times,resulting in failure to meet operational requirements,influencing the normal function of the tunnel,and causing harm to the foundation structure,personnel,and property in severe cases.This article formulates a finite element numerical computation model for solid elements using three-dimensional elastic body theory and integrates field measurements to substantiate and ascertain the crucial parameter configurations of the finite element model.By proposing a comprehensive startup timing function for high-frequency dynamic machines under different startup conditions,simulating the frequency andmagnitude variations during the startup process,and suggesting functions for changes in frequency and magnitude,a simulated startup schedule function for high-frequency machines is created through coupling.Taking into account the selection of the transient dynamic analysis step length,the dynamic response results for the lower dynamic foundation during its fundamental frequency crossing process are obtained.The validation checks if the structural magnitude surpasses the safety threshold during the critical phase of unit startup traversing the structural resonance region.The design recommendations for high-frequency units’dynamic foundations are provided,taking into account the startup process of the machine and ensuring the safe operation of the tunnel.

Special Issue on Electromechanical Coupling Design for Electronic Equipment

With the development of electronic equipment to high accuracy, high density, high frequency, and atrocious ser- vice environment, the functional surface in this type of equipment has increasingly serious problems,

Design Method of Equipment Optimization Development Based on Standardization Theory

The matters of equipment optimization development are usually discrete,fuzzy and non-quantitative.It is difficult directly to optimize the equipment development with a mathematical model.A set of methods for designing the equipment optimization development with six dimensions and eight main elements is established based on the theory and method of standardization.The top-tier design space of systematic development of equipment is built up by the relations of basic models,series and model spectrums.The relations of time and space for equipment optimization development are established.The design processes of a six dimension systematic space are expounded.The connotation of each plan in the main system space is analyzed.A design method for an entire equipment is established with standardization theory.The coordinating design methods of equipment technical system and the optimization design methods of equipment integration are discussed.The design methods for universalization and serialization of components and parts are established.The design methods of equipment optimization development highlight the relations of the basic model of platform,the serialization of platform basic models,the modularization of equipment functions,the model spectrum of variant equipment,and the universalization and serialization of components and parts.

Vibration Isolation Characteristics of Impedance-balanced Ship Equipment Foundation under Unbalanced Excitation

A new type of impedance-balanced ship equipment foundation structure based on the principle of impedance balancing using a“discontinuous panel-vibration isolation liquid layer-foundation structure”is proposed to solve the problem of poor low-frequency vibration isolation of the foundation under unbalanced excitation of shipboard equipment.Based on the finite element method,the influence of characteristic parameters of the foundation panel structure on its vibration reduction characteristics under unbalanced excitation is explored.The results show that the vibration isolation level of the impedance-balanced foundation is 10 dB higher than the traditional foundation in the low-frequency band of 10-500 Hz when subjected to combined excitation of concentrated force and moment.Increasing the thickness of the impedance-balanced foundation panel can enhance the isolation effect.Increasing the number of sub-panels can effectively reduce the vibration response of the foundation panel and enhance the isolation performance of the foundation.The connection stiffness between sub-panels has a small effect on the isolation performance of the foundation.

Research and design of the main equipments and structure of Xiangjiaba shiplift

The type of pinion and rack vertical shiplifts has been developed in recent a couple of years in the construction of dams.But the design methods and methodologies have rarely been discussed in literature.The Xiangjiaba shiplift is the second shiplift of this type following the Three Gorges shiplift.Being aimed at the technological rationality of the design in synthetically considering security,economy and applicability,this paper presents the research results of some vital issues relating the design of the Xiangjiaba shiplift,including the determination of design water depth of ship chamber based on fluid numeral computation and physical model test,the optimum design of general layout of main equipments and the civil structure of the Xiangjiaba shiplift,the finite element method(FEM) analysis of stress,vibration modes and the buckling of ship chamber,antiseismic research and the design of structures and mechanisms of the shiplift and the optimum design of driving mechanisms.This research provides the theoretical basis for the design of the Xiangjiaba shiplift.The design principles and research methods are valuable for the design of the same type of shiplifts.

Optimal Selection Model of Equipment Design Scheme Based on Set Pair Analysis

Selecting the optimal one from similar schemes is a paramount work in equipment design.In consideration of similarity of schemes and repetition of characteristic indices,the theory of set pair analysis(SPA)is proposed,and then an optimal selection model is established.In order to improve the accuracy and flexibility,the model is modified by the contribution degree.At last,this model has been validated by an example,and the result demonstrates the method is feasible and valuable for practical usage.

Research on the Design Method of Equipment in Service Assessment Subjects

Combined with equipment activities such as combat readiness,training, exercises and management, it is proposed that the design of equipment in-service assessment subjects should follow the principles of combination, stage and operability. Focusing on the design of equipment in-serviceassessment subjects, a design method for in-service assessment subjects basedon the combination of trial and training mode is proposed. Based on theactual use of high-equipment use management and training and the established indicator system, the army’s bottom-level equipment activity subjectsand bottom-level assessments are combined. The indicators are mapped andanalyzed. Through multiple rounds of iterations, the mapping relationshipbetween in-service assessment indicators and military equipment activitysubjects is established. Finally, the equipment activity subjects whose data iscollected (reflecting the underlying assessment indicators) are generated inservice assessment subjects. The orthogonal test method is used to optimizethe samples in the assessment subjects to form an in-service assessmentimplementation plan. Taking a certain type of armored infantry fightingvehicle as an example, the sample optimization design of the initially generatedin-service assessment subjects is analyzed. It provides methods and ideas tocarry out in-service assessment work.

On Syllabus Design for the Specialty of Electromechanical Equipment Maintenance and Management in Vocational College

We carried out researches on the syllabus design for the specialty of electromechanical equipment maintenance & management in vocational college. Our researches involve the following aspects: (1) The training objective of the specialty; (2) the curriculum system; (3) The teaching methodology; and (4) Field training.

满足DNV船级符号Clean(Design)要求的轮机设备订货及系统设计

为有效避免在船舶产品设计过程中出现疏漏,研究挪威船级社船级符号Clean(Design)对轮机设备订货、系统设计和舱柜布置的最新要求,并对各设备和系统的特殊要求及设计原则进行梳理和归纳。用于处理污染物的设备主要包括油水分离器、污水处理装置和焚烧炉,涉及的船舶系统主要包括舱底水系统、生活污水处理系统、泡沫灭火系统和艉管滑油系统等。该研究可供满足该规范要求的环保型船舶产品的设计参考。

Characteristic Period Value of the Seismic Design Response Spectrum of UHV Electrical Equipment

Characteristic period is an important parameter of the seismic design response spectrum.There is important theoretical significance and engineering application value to the study of the characteristic period of seismic design response spectrum of ultra high voltage(UHV)electrical equipment.In this paper,1448 horizontal earthquake records within the world scope including the United States and Japan for Site Class Ⅲ were analyzed.Results show that both magnitude and epicentral distance have great influence on the characteristic period.About80% of characteristic periods of strong earthquake records are about 0.9s.Statistical analysis was conducted on the seismic hazard assessment results of 312 projects of China in recent years,and it is found that about 70% of characteristic periods are about 0.9s.Combined with the related code comparison and analysis,it is suggested that the characteristic period of the seismic design response spectrum of UHV electrical equipment should select 0.9s in order to effectively guarantee the seismic safety of UHV electrical equipment.

Practice and Exploration of Economic Benefit Evaluation of Medical Equipment in Our Hospital

Objective The evaluation index of medical equipment's economic benefit is based on the usage of medical equipment,the traditional data collection method is time-consuming,laborious and not entirely accurate.The usage of medical equipment is obtained by designing data query statements from the HIS system.Methods First the charging items are in correspondence with the device's name included,second fees and other relevant data are extracted from charging module in HIS.Through a rough estimate of the recovery period and an increase or decrease ratio,the economic benefit of the medical equipment can be analyzed.Results Through the method of the benefit analysis of the medical equipment,we can clearly find out the different economic benefit of the equipment,and finally analyze the reasons.Conclusion Practice has proved that,this methad,it can greatly reduce human,material resources required in data collection and improve the accuracy of the data.It can help hospital managers timely to grasp the operating costs of medical equipment and other information,and also provide scientific data for hospital managers when they purchase reasonable medical equipment.

Adhere to the direction of detailization in CC technology and equipment

Since the excessive capacity in steelmaking and continuous casting at present,and the limited development margin of CC technology and equipment in scale,the further development must be made in a profound and detailized way.This paper enumerates the items of CC technology and equipment,which need to be detailized from several aspects such as roll arrangement design,equipment design and production operation,and it points out that detailization is the future direction of CC technology and equipment.The items in roll arrangement design include eliminating periodic meniscus fluctuation by adjusting space between rolls reasonably;taking special measures to avoid dangerous regions of casting speed,in order to reduce the center porosity and centerline crack of slab;optimizing the major radius and the length of outer arc of caster before straightening point to avoid dangerous region of casting speed.The items in equipment design include choosing a suitable structure of support and guiding roll according to the concrete conditions of caster;according to bulging shape of slab,thinking more about restriction of shell to bulging force, discussing the force on rollers,optimizing split roll to support slab;safety factor should be considered together with calculation method of the bearing nominal static load.The items in aspects of continuous casting operation include the delicacy division and the function-positioning of operation modes for CC machine due to the consideration of dynamic soft reduction;monitoring and controlling system of CC machine must be further detailized to improve the stability of production operation and slab quality.In addition to the three aspects mentioned above,this article points out many other items also,such as homogenization of secondary cooling of slab,quality control of surface and internal of slab,and so on.This article emphasizes,some key technologies need to be researched also,and all these researches will never stop.

Consideration and development of anaerobic fermentation equipment on solid organic rejectamenta

This article, based on investigation and analysis, existed anaerobic fermentation equipment, with a view to the production of high-latitude area, pointed out the thought of exploiting efficient anaerobic fermentation equipment, including： the settting independent equipment of acidogenic phase and methanogenic phase; the applying conbination of AF and UASB in methanogenic phase; adopting efficient sludge inverse flowing equipment and the technique of flora enrichment, and efficient method of saving energy and thermal retardation; adopting autocontrol which could make the equipment run efficiently and stably.

Failure Mode Effects and Criticality Analysis Method of Armored Equipment Based on Testability Growth

In view of the low level testability of armored equipment,the important significance of armored equipment testability growth is discussed in this paper.The failure mode effects and criticality analysis( FMECA) method to realize testability growth is introduced.Centering on the testability growth demands of new armored equipment,the deficiencies of traditional FMECA are analyzed.And an enhanced FMECA( EFMECA) method is proposed.The method increases the analysis contents,combines the information before the failure occurrence and impending failure modes together organically.Then the failure symptoms is analyzed,the failure modes and effects is determined,and the state development trend is predicted.Finally,the application of EFMECA method is illustrated by the example of the failure mode of typical armored equipment engine.

Problems Involving New Technology Application for Environmental Protection Equipment

The numerous environmental protection equipments for desulfuration,denitration,and precipitation have been installed in the domestic coal-fired power plants,while the investment and energy consumption of the units increase correspondingly.To reduce the operational cost and initial investment as much as possible,the working processes of the environmental protection equipments are optimized in the design and some new technologies are adopted for energy saving.These technologies include the SCR,SNCR,combined SCR and SNCR for denitration device,system without gas-gas heater design for desulfuration,desulfuration system without bypass,booster fan and induced draft fan integrated,stack and cooling tower integrated and so on.However,such measures may cause some new problems during the operation of the equipment.The problems are summarized and analyzed thoroughly and the feasible methods are provided to solve them,which could decrease the operational risk of units.The present discussion can also improve the further design of environmental protection equipments to ensure the long-term steady operation of the units.

基于食品冻结曲线的小龙虾液氮速冻装备设计与试验

针对液氮速冻产品冻裂率高、液氮损耗量大的问题,基于食品冻结曲线,设计三腔体液氮速冻设备,包括预冷腔(4.2 m,-70℃)、结晶腔(5.8 m,-100℃)和深冷腔(5.0 m,-120℃)。相较于单腔体液氮速冻设备(15.0 m,-100℃),三腔体液氮速冻设备使预包装调理小龙虾的冻结时间缩短10.0%,冻裂率降低40.4%,液氮节约15.0%;质构(硬性、弹性、内聚性、回复性、咀嚼性)和色泽(L*,b*)显著改善,挥发性盐基氮显著降低,水分、盐溶性蛋白和感官(色泽和质地)品质显著提高。研究为液氮速冻技术和装备的改进提供参考和借鉴。

航天总体设计的智慧研发模式

新一代航天复杂装备的发展,亟须改变传统研制模式,提升总体设计水平,缩短研制周期,降低试验成本。同时,我国航天装备研制过程积累的大数据资源没有形成有效的知识积累与重用手段,并且多专业强耦合的总体设计研制流程信息化程度低,导致专业内部和专业之间协同不高效,难以驱动装备总体方案设计实现敏捷、高效、最优。因此,如何建设智慧研发体系成为当前航天总体设计面向数字化、智能化融合发展的主要焦点问题。本文介绍了航天装备总体设计的智慧研发模式,分析了难点与需求,提出了实施途径、模型体系、研制流程和支撑平台架构,以研制流程高效可控、数据智能学习、知识驱动设计、系统耦合验证为构建思路,用于指导建设新一代航天装备总体设计的智能化、协同化研发环境,支撑产品自主研发能力和产品研发活动规范高效地开展,指导设计持续改进,推动航天装备数字化研制。

基于区块链技术的医疗设备采购管理系统的设计与实现

目的针对传统采购资料易丢失和被篡改,无法保证采购数据安全性的问题,设计一套基于区块链技术的医疗设备采购管理系统。方法系统采用Python编程语言设计,使用Django框架、SQLite数据库,基于区块链技术构建区块链服务器、采购人客户端、采购机构客户端、供应商客户端、监管机构客户端,将整个采购过程中的数据全部进行区块化处理,使得所有数据保存完整,不能被随意窜改,最终实现具有防篡改特性并支持溯源的医疗设备采购管理系统。结果该系统各模块以及防篡改机制均通过测试验证;各模块的平均响应时间均<2 s,响应速度快;模拟网络及身份验证安全测试的结果显示,其安全性能均满足要求。结论将区块链技术应用于医疗设备采购管理系统是可行的方案,其保证了整个采购流程中产生的数据完整可靠并防止被篡改,使得采购信息能够在系统中完整留痕,从而对医疗设备的采购进行全方位管理。

新一代快速部署方舱医院配套医疗设备的定制化设计方案

方舱医院被广泛用于灾害救援、战场救治、突发公共卫生事件防控等场景。目前,我国已进入第三代方舱医院的研制阶段。方舱医院的整体效能与配套医疗设备的性能直接相关。在研制阶段探讨方舱医院配套医疗设备的定制化设计方案,可保证医疗设备的配置与方舱医院的功能相匹配,从而更好地发挥方舱医院的整体效能。该研究针对方舱医院中占主体地位的急救设备、检验设备和影像设备,详细分析定制化设计方案。定制化设计的重点在于有限空间适应性、功能集成性、可快速部署、轻便性、抗震性、极端环境适用性、以及影像设备的低剂量高品质成像,并注重智能化功能融入。该研究可用于指导方舱医院配套医疗设备的定制化研制、选型及升级改造。

《起重机械安全技术规程》对机械式停车设备设计的要求

我国是全球机械式停车设备生产和使用第一大国。特种设备安全技术规范是机械式停车设备设计、制造、安装、维修、检验检测、使用管理和安全监管的强制性要求。本文从提高机械式停车设备的本质安全角度,详细介绍了即将施行的特种设备安全技术规范TSG 51-2023《起重机械安全技术规程》中对机械式停车设备设计的具体规定,包括设计的基本要求、主要金属结构、主要工作机构、主要零部件、主要控制系统、安全保护装置等,分析了该规程与现行相关安全技术规范的主要区别,以期帮助生产、使用、检验检测单位正确理解和使用。