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.

Review of the Analysis and Suppression for High-frequency Oscillations of the Grid-connected Wind Power Generation System

High-frequency oscillation(HFO)of gridconnected wind power generation systems(WPGS)is one of the most critical issues in recent years that threaten the safe access of WPGS to the grid.Ensuring the WPGS can damp HFO is becoming more and more vital for the development of wind power.The HFO phenomenon of wind turbines under different scenarios usually has different mechanisms.Hence,engineers need to acquire the working mechanisms of the different HFO damping technologies and select the appropriate one to ensure the effective implementation of oscillation damping in practical engineering.This paper introduces the general assumptions of WPGS when analyzing HFO,systematically summarizes the reasons for the occurrence of HFO in different scenarios,deeply analyses the key points and difficulties of HFO damping under different scenarios,and then compares the technical performances of various types of HFO suppression methods to provide adequate references for engineers in the application of technology.Finally,this paper discusses possible future research difficulties in the problem of HFO,as well as the possible future trends in the demand for HFO damping.

Effects of unilateral superimposed high-frequency jet ventilation on porcine hemodynamics and gas exchange during one-lung flooding

BACKGROUND Superimposed high-frequency jet ventilation(SHFJV)is suitable for respiratory motion reduction and essential for effective lung tumor ablation.Fluid filling of the target lung wing one-lung flooding(OLF)is necessary for therapeutic ultrasound applications.However,whether unilateral SHFJV allows adequate hemodynamics and gas exchange is unclear.AIM To compared SHFJV with pressure-controlled ventilation(PCV)during OLF by assessing hemodynamics and gas exchange in different animal positions.METHODS SHFJV or PCV was used alternatingly to ventilate the non-flooded lungs of the 12 anesthetized pigs during OLF.The animal positions were changed from left lateral position to supine position(SP)to right lateral position(RLP)every 30 min.In each position,ventilation was maintained for 15 min in both modalities.Hemodynamic variables and arterial blood gas levels were repeatedly measured.RESULTS Unilateral SHFJV led to lower carbon dioxide removal than PCV without abnormally elevated carbon dioxide levels.SHFJV slightly decreased oxygenation in SP and RLP compared with PCV;the lowest values of PaO_(2) and PaO_(2)/FiO_(2) ratio were found in SP[13.0;interquartile range(IQR):12.6-5.6 and 32.5(IQR:31.5-38.9)kPa].Conversely,during SHFJV,the shunt fraction was higher in all animal positions(highest in the RLP:0.30).CONCLUSION In porcine model,unilateral SHFJV may provide adequate ventilation in different animal positions during OLF.Lower oxygenation and CO_(2) removal rates compared to PCV did not lead to hypoxia or hypercapnia.SHFJV can be safely used for lung tumor ablation to minimize ventilation-induced lung motion.

电液3-UPS/S并联稳定平台参数振动特性分析

针对电液3-UPS/S并联稳定平台驱动液压缸的压力脉动所产生的参数振动,建立了稳定平台的参数振动方程并利用多尺度法求解了主共振响应与组合共振响应的一次近似解;分析了主共振与组合共振响应特性以及振动幅值在初始工作空间内的变化规律,最后采用四阶龙格库塔法与模态试验对参数振动模型进行验证。结果表明:数值解与理论解之间的最大误差为4.20%,固有频率理论值与试验值之间的最大误差为4.66%,可验证参数振动模型的正确性。

基于NB-IoT的UPS智能在线监测系统的设计

针对UPS机房在运行过程中无人监守,工作人员无法及时排查故障的问题,设计并实现了一套基于ARM和NB-IoT的UPS智能在线监测系统,由检测终端、云服务器和监管中心组成;检测终端使用各类传感器和检测电路获取多个UPS设备的输入输出电压和电流、负载率、蓄电池电量等数据以及机房温湿度环境参数,通过无线模块发送给云服务器,监管中心从云服务器获取数据,用户可以登录监管中心远程查询UPS的工作数据;经测试,系统能够实现对UPS各项数据的采集和无线传输,可以通过监管中心实时查询UPS工作状态以及下发指令,能达到实时监控的效果;具有数据测量准确,实时性响应良好等特点,减少了管理人员的工作量,提高了UPS的管理效率。

综合性医院UPS选型及运维关键问题探讨

通过文献研究法,根据应用场景差异,设计UPS选型流程,明确选型策略,同时借助信息化手段,以全生命周期运维为思路,在医院后勤智慧运维平台架构上拓展UPS运维模块,设计UPS巡检方案并实施,解决了UPS选型及运维过程中存在的问题,提升了运维效能。

化工仪表UPS配置管理及维护探讨

不间断电源(UPS,Uninterrupted power supply),由电力变流器、储能装置(如蓄电池)和开关(电子式、机械式或混合式)等组合而成,在供电中断后能持续一定供电时间的电源设备[1]。随着技术的发展,UPS不间断电源应用范围逐渐扩大,特别在电信、石油、化工等领域得到了广泛的应用。石油化工企业生产装置电力设计技术规范规定一级负荷中当生产装置工作电源突然中断时,为确保安全停车,避免引起爆炸、火灾、中毒、人员伤亡、关键设备损坏,或事故一旦发生能及时处理,防止事故扩大,保证关键设备,抢救及撤离工作人员,而必须保证用电的负荷,应视为一级负荷中特别重要负荷,特别重要负荷必须设置UPS电源[2]。一般情况下,化工装置一级负荷都基本配备UPS电源,通过我司多年来对UPS电源应用过程中的经验,探讨化工仪表UPS电源的配置、管理、维护等要点问题,优化UPS配置,不断改善管理及维护能力。

广播电视制播工程项目中UPS的选用研究

对于广播电视制播工程项目,为确保直播内容安全播出和内容编辑的时效性,与直播相关的系统和内容编辑系统的核心设备需要接入不间断电源(Uninterruptible Power Supply,UPS)供电回路。因此,在供配电系统设计过程中,如何选择合适的UPS电源设备技术架构成为一个关键问题。主要探讨了广播电视制播工程项目中UPS电源设备的选用,对UPS高频机和UPS工频机进行了比较分析,进而给出了广播电视制播工程中UPS电源设备的选用策略。

基于UPS策略自我训练的半监督语义分割

为提高半监督语义分割的效果,文章提出一种损失归一化技术结合UPS策略的半监督语义分割网络SPNS。利用损失归一化技术缓解标准损失函数的自我训练不稳定问题;UPS策略是结合不确定性估计和消极学习的技术,通过计算输出值的不确定性作为另一种阈值,用以挑选可靠的伪标签,最后利用生成的伪标签和标记数据完成半监督语义分割任务。SPNS方法在PASCAL·VOC数据集上相对于只使用标记数据训练有着+2.06的效果提升,与其他方法相比也有一定提升。

UPS电控系统在降低海上平台电力关断风险中的应用

阐述钻采平台UPS系统的故障原因,通过对UPS系统馈线柜开关保护方式的优化升级,将欠压脱扣优化为分励脱扣,并对UPS电控系统、镍铬蓄电池备用电源系统优化,从而解决设计缺陷。

基于电子电路原理的UPS故障分析与解决方案研究

不间断电源(Uninterruptible Power Supply,UPS)作为电力保障系统的重要组成部分,在现代电力系统中扮演着至关重要的角色。然而,由于UPS具有复杂的电子电路结构,在实际运行中常常面临各种故障问题,不仅影响系统的可靠性和稳定性,而且可能导致重大的经济损失和安全风险。因此,深入分析UPS故障,并提出有效的解决方案具有重要意义。文章通过研究基于电子电路原理的UPS故障分析与解决方案,梳理相关理论和实践经验,为UPS故障诊断与维修提供参考与指导。

Kinematic deformation and intensity assessment of the 2021 Maduo M_(S)7.4 earthquake in Qinghai revealed by high-frequency GNSS

Rapid acquisition of the kinematic deformation field and seismic intensity distribution of large earthquakes is crucial for postseismic emergency rescue,disaster assessment,and future seismic risk research.The advancement of GNSS observation and data processing makes it play an important role in this field,especially the high-frequency GNSS.We used the differential positioning method to calculate the 1 HZ GNSS data from 98 sites within 1000 km of the M_(S)7.4 Maduo earthquake epicenter.The kinematic deformation field and the distribution of the seismic intensity by using the peak ground velocity derived from displacement waveforms were obtained.The results show that:1)Horizontal coseismic response deformation levels ranging from 25 mm to 301 mm can be observed within a 1000 km radius from the epicenter.Coseismic response deformation on the east and west sides shows bilateral asymmetry,which markedly differs from the symmetry presented by surface rupture.2)The seismic intensity obtained through high-frequency GNSS and field investigations exhibits good consistency of the scope and orientation in the high seismic intensity area,although the former is generally slightly smaller than the latter.3)There may exist obstacles on the eastern side of the seismogenic fault.The Maduo earthquake induced a certain tectonic stress loading effect on the western Kunlun Pass-Jiangcuo fault(KPJF)and Maqin-Maqu segment,resulting in higher seismic risk in the future.

高频UPS在变电站交直流电源系统中的应用

高频UPS是高频开关电源技术在不间断电源领域的应用成果。其内部整流器与逆变器的开关频率高达几十甚至上百kHz,没有隔离变压器,整机效率更高,体积更小。在220kV及以下电压等级变电站交直流系统中,高频UPS的成本、体积、输出质量及工作效率等一系列指标优于工频机器,而其自身在负载能力、工作环境要求等方面的天然劣势也可以得到有效的规避。笔者认为应当加大高频UPS在低电压等级变电所中的应用,高频UPS在未来会如同高频开关电源取代线性电源一样逐步取代相应的工频产品。

Efficient activation of the Co/SBA-15catalyst by high-frequency AC-DBD plasma thermal effects for toluene removal

Dielectric barrier discharge(DBD)plasma excited by a high-frequency alternating-current(AC)power supply is widely employed for the degradation of volatile organic compounds(VOCs).However,the thermal effect generated during the discharge process leads to energy waste and low energy utilization efficiency.In this work,an innovative DBD thermally-conducted catalysis(DBD-TCC)system,integrating high-frequency AC-DBD plasma and its generated thermal effects to activate the Co/SBA-15 catalyst,was employed for toluene removal.Specifically,Co/SBA-15 catalysts are closely positioned to the ground electrode of the plasma zone and can be heated and activated by the thermal effect when the voltage exceeds 10 k V.At12.4 k V,the temperature in the catalyst zone reached 261℃ in the DBD-TCC system,resulting in an increase in toluene degradation efficiency of 17%,CO_(2)selectivity of 21.2%,and energy efficiency of 27%,respectively,compared to the DBD system alone.In contrast,the DBD thermally-unconducted catalysis(DBD-TUC)system fails to enhance toluene degradation due to insufficient heat absorption and catalytic activation,highlighting the crucial role of AC-DBD generated heat in the activation of the catalyst.Furthermore,the degradation pathway and mechanism of toluene in the DBD-TCC system were hypothesized.This work is expected to provide an energy-efficient approach for high-frequency AC-DBD plasma removal of VOCs.

高频UPS和锂电池应用于半导体工厂的多元化评价

文章介绍了高频UPS和锂电池在半导体工厂实际负载工况应用场景下的性能测试。从供电可靠性、安全高效、易扩容、易维护等方面评估了高频模块化UPS,说明了高频模块化UPS应用于半导体晶圆制造厂中,对含有冲击性电流的感性负载的良好适用性。

基于UPS通信的远程监控与故障诊断技术探究

UPS(不间断电源)作为关键的电力保障设备,在各类关键应用中发挥着至关重要的作用。然而,传统的UPS监控与故障诊断方式存在着局限性,如实时监控能力不足、故障诊断准确性不高等。为解决这一问题,基于UPS通信的远程监控与故障诊断技术应运而生。该技术利用UPS的通信接口,通过网络实现对UPS设备的远程监控和故障诊断,从而提高了UPS系统的可靠性和稳定性。本文旨在探究基于UPS通信的远程监控与故障诊断技术的关键原理、方法和应用,为提升UPS系统的运行管理水平提供技术支持。

UPS电源系统在电视播出系统中的应用

目前,各地市级以上电视播出系统较为复杂,电力供应直接影响着广播电视安全播出。UPS电源作为备用电源,发挥着重要的作用。本文介绍了后备式、在线式、在线式互动三种较常见的UPS电源系统,通过增加UPS系统的抗压,合理使用UPS系统,建立健全管理制度、激励制度等手段,可以提升电源系统管理能力,提高安全播出水平,为读者提供借鉴。

Therapeutic efficacy of methylprednisolone sodium succinate via diverse administration routes for mid-to high-frequency sudden sensorineural hearing loss

BACKGROUND Sudden sensorineural hearing loss(SSNHL),characterized by a rapid and unexplained loss of hearing,particularly at moderate to high frequencies,presents a significant clinical challenge.The therapeutic use of methylprednisolone sodium succinate(MPSS)via different administration routes,in combination with conventional medications,remains a topic of interest.AIM To compare the therapeutic efficacy of MPSS administered via different routes in combination with conventional drugs for the treatment of mid-to high-frequency SSNHL.METHODS The medical records of 109 patients with mid-to high-frequency SSNHL were analyzed.The patients were divided into three groups based on the route of administration:Group A[intratympanic(IT)injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection],Group B(intravenous injection of MPSS combined with mecobalamin and Ginkgo biloba leaf extract injection),and Group C(single IT injection of MPSS).The intervention effects were compared and analyzed.RESULTS The posttreatment auditory thresholds in Group A(21.23±3.34)were significantly lower than those in Groups B(28.52±3.36)and C(30.23±4.21;P<0.05).Group A also exhibited a significantly greater speech recognition rate(92.23±5.34)than Groups B and C.The disappearance time of tinnitus,time to hearing recovery,and disappearance time of vertigo in Group A were significantly shorter than those in Groups B and C(P<0.05).The total effective rate in Group A(97.56%)was significantly greater than that in Groups B and C(77.14%and 78.79%,χ^(2)=7.898,P=0.019).Moreover,the incidence of adverse reactions in Groups A and C was significantly lower than that in Group B(4.88%,3.03%vs 2.57%,χ^(2)=11.443,P=0.003),and the recurrence rate in Group A was significantly lower than that in Groups B and C(2.44%vs 20.00%vs 21.21%,χ^(2)=7.120,P=0.028).CONCLUSION IT injection of MPSS combined with conventional treatment demonstrates superior efficacy and safety compared to systemic administration via intravenous infusion and a single IT injection of MPSS.This approach effectively improves patients'hearing and reduces the risk of disease recurrence.

中小型通信机房的UPS冗余方案分析

阐述为了增强通信机房供电的稳定性,通常UPS会采取冗余的方式,UPS冗余方案是多样的。通过对几套UPS冗余方案的优缺点分析,为机房改造及建设选用UPS冗余方式提供参考。

一种单相在线式UPS的设计

UPS为生产设备持续运行提供稳定电力供应。设计了一个输出为交流30 V的单相不间断电源。电路由市电经过整流电路、升压电路、EG8010和IRS2113S芯片控制驱动的单相桥式逆变电路、辅助电源等组成。当市电发生断电,自动切换至24 V直流稳压电源(模拟蓄电池)供电,以保障设备的正常工作。经测试,本设计输出正弦电压波形失真度小、电压调整率和负载调整率不大于0.5%,同时还具有过流保护、过压保护的功能。