Dynamic Responses of Rotor Drops onto Double-decker Catcher Bearing

In an active magnetic bearing （AMB） system, the catcher bearings （CBs） are indispensable to protect the rotor and stator in case the magnetic bearings fail. Most of the former researches associated with CBs are mainly focused on the dynamic responses of the rotor drops onto traditional single-decker catcher bearings （SDCBs）. But because of the lower limited speed of SDCB, it cannot withstand the ultra high speed rotation after rotor drop. In this paper, based on the analysis of the disadvantages of SDCBs, a new type of double-decker catcher bearings （DDCBs） is proposed to enhance the CB work performance in AMB system. In order to obtain thc accurate rotor movements before AMB failure, the dynamic characteristics of AMB are theoretically derived. Detailed simulation models containing rigid rotor model, contact model between rotor and inner race, DDCB force model as well as heating model after rotor drop are established. Then, using those established models the dynamic responses of rotor drops onto DDCBs and SDCBs are respectively simulated. The rotor orbits, contact forces, spin speeds of various parts and heat energies after AMB failure are mainly analyzed. The simulation results show that DDCBs can effectively improve the CBs limit rotational speed and reduce the following vibrations, impacts and heating. Finally, rotor drop experiments choosing different types of CBs are carried out on the established AMB test bench. Rotor orbits, inner race temperatures as well as the rotating speeds of both inner race and intermediate races after rotor drop are synchronously measured. The experiment results verify the advantages of DDCB and the correctness of theoretical analysis. The studies provide certain theoretical and experimental references for the application of DDCBs in AMB system.

Investigation of ex-vessel core catcher for SBO accident in VVER-1000/V528 containment using MELCOR code

To mitigate consequences of core melting,an ex-vessel core catcher is investigated in this study.Instructions should be obeyed to cool down the corium caused by core melting.The corium destroys the reactor containment and causes radioactive materials to be released into the environment if it does not cool down well.It is important to build a core catcher system for the reception,localization,and cool down of the molten corium during a severe accident resulting from core melting.In this study,the role of a core catcher in the VVER-1000/v528 reactor containment during a station black out(SBO)accident is evaluated using the MELCOR1.8.6 code.In addition,parametric analyses of the SBO for(i)SBO accidents with emergency core cooling system(ECCS)operation,and(ii)without ECCS operation are performed.Furthermore,thermal–hydraulic analyses in dry and wet cavities with/without water are conducted.The investigations include the reduction of gases resulting from molten–corium–concrete interactions(H_(2),CO,CO_(2)).Core melting,gas production,and the pressure/temperature in the reactor containment are assessed.Additionally,a full investigation pertaining to gas release(H_(2),CO,CO_(2))and the pressure/temperature of the core catcher is performed.Based on MELCOR simulations,a core cavity and a perimeter water channel are the best options for corium cooling and a lower radionuclide release.This simulation is also theoretically investigated and discussed herein.The simulation results show that the core catcher system in addition to an internal sacrificial material reduces the containment pressure from 689 to 580 kPa and the corresponding temperature from 394 to 380 K.Furthermore,it is observed that the amount of gases produced,particularly hydrogen,decreased from 1698 to 1235 kg.Moreover,the presence of supporting systems,including an ECCS with a core catcher,prolonged the core melting time from 16,430 to 28,630 s(in an SBO accident)and significantly decreased the gases produced.

Dynamics of Rotor Drop on New Type Catcher Bearing

In an active magnetic bearing(AMB)system,the catcher bearings(CBs)are indispensable to protect the rotor and stator in case the magnetic bearings fail or overload.A new CB structure composed of two ball bearings is introduced.Detailed simulation models containing contact model between rotor and inner race,double-decker catcher bearing(DDCB)model as well as single-decker catcher bearing(SDCB)model are established using multibody dynamics simulation software MSC.ADAMS.Then,using those established models,the rotor orbits and the contact forces between rotor and inner race are simulated respectively after rotor drop on DDCBs and SDCBs.The simulation result shows that the rotor vibration range using DDCBs is significantly smaller than that using SDCBs;the maximum contact forces drop about 15%—27% compared with the contact forces using SDCBs.Finally,the test bench for the rotor drop experiments is built and the rotor drop experiments for different types of CBs are carried out.Labview data acquisition system is utilized to collect the displacement of rotor and the rotating frequencies of both inner race and intermediate races after rotor drop.The experimental results are comparatively analyzed,and the conclusion that DDCB can help to reduce vibration amplitude and collision force is obtained.The studies can provide certain theoretical and experimental references for the application of DDCBs in AMB system.

A Brief Discussion about the Creating and Portraying of Holden Caulfield in The Catcher in the Rye

The Catcher in the Rye,J.D. Salinger's first long fiction,was one of his most famous and successful works. It not only influenced American novels written afterwards,for example,Evan Hunter's Last Summer,Sylvia Plath's The Bell Jar,but also influenced the American society. Take the American film industry which was so good at chasing the audience's interest for a typical example:a large numebr of movies,such as Rebel Without A Cause,American Graffiti,Dirty Dancing,The graduate,and so on:they wouldn't have been filmed like that if The Catcher in the Rye didn't go front as a model. Then,can we really find any big differences between the anxiety ex-pressed by Holden and that by the music and words of Jewel,the Green Day,and the Smashing Pumpkins?

No Place for Adolescence to Rest——The Symbolic Scenes on Holden's Journey in The Catcher in the Rye

By releasing the book The Catcher in the Rye,J.D.Salinger received an immediate popularity of his writing career.Hissymbolic use of language has been thoroughly researched but the symbolic scenes which make up Holden's life stage,especiallythe symbolic connotations of ironic resting places in the novel,such as bed,couch and bedroom,has not been paid much attention.It tries to analyse the four scenes: on Holden's history teacher's bed,on the hotel bed with a prostitute,in his sister's bedroom,and on his English teacher's couch,and aims to discover his spiritual chaos as well as adolescent desires in the real world,demon-strating that there is no place for adolescent Holden to rest after he chooses his own stage of scenes in his life.

Experimental study on sand particles accumulation,migration and separation efficiency in slug catcher

Sand production often leads to the failure of production equipment on offshore platform.Therefore,a new idea has been put forward,which is installing cyclone or baffle in the internal of the slug catcher for better sand control.In this paper,an experimental study is presented,which mainly includes sand particles accumulation shape,migration law and separation performance.The results suggest that the accumulation area is mainly divided into two zones:the crowded settlement zone and the free settlement zone.The crowded settlement zone has a special shape,which can be characterized by two parameters:accumulation length and accumulation angle.Axial sampling analysis shows obvious particle classification.Median particle size decreases with the increase of the axial distance,and the range of particle size distribution narrows gradually.The separation experiment shows that the gas velocity has the greatest influence on the separation efficiency.When the gas velocity is 14 m·s^ 1,the separation efficiency drops sharply,which can be abated by installing cyclone separator.In addition,the separation efficiency tends to be a constant under different gas velocities by installing baffle with appropriate height.Then the effectiveness and rationality of installing internal components can be strongly proved.All these provide important guidance for maximizing the sand control function of the slug catcher.

小说代词间接回指语汉译的伦理研究——以The Catcher in the Rye两个汉译本为例

本文以翻译伦理为观照,以The Catcher in the Rye的施咸荣、孙仲旭两个汉译本为例,探讨代词间接回指语的汉译。结果表明:(1)代词间接回指语的汉译方法从宏观上看,以直译为主,辅之以回指语的去除、明晰化和回指语的增益、转换等,虽然施译本的直译比例远超孙译本;当涉及到具体句子,不同译本中代词间接回指语的译法颇有差异;(2)"文化转向"背景下的翻译伦理及其再现、服务、交际、规范等伦理细则是一个合适的参照和分析手段,可以从微观上分析代词间接回指语各译例的得失;(3)两个汉译本服务于各自的时代,施译更多地想要忠实原文和作者,而孙译兼顾作者和读者。虽然总体上在回指语翻译方面孙译本超过施译本,但都体现了翻译伦理,因此各有千秋,说明了译者风格的客观存在。

A Study on the Interaction Between The Catcher in the Rye and the Readers From the Perspective of Iser’s Reader-Response

The Catcher in the Rye has been popular with readers since its publication,and critics at home and abroad have also conducted a lot of research on it.But they mainly proceed from the author and the text to evaluate and analyze,ignoring the readers who are essential participants in text interpretation in the eyes of reader-response critics.In order to make up for this shortcoming,this article will take Iser’s reader-response criticism as a research perspective,starting from the three aspects of implied reader,response-inviting structure,and gaps to explore the interaction between the text of The Catcher in the Rye and the readers during the reading process.This research is expected to provide a new interpretation of this novel and provide reference for future research in related fields.

Translation of The Catcher in the Rye from the Perspective of Skopos Theory——A Case Study of Sun Zhongxu's Translation Work

This paper analyzes the E-C translation of the book The Catcher in the Rye from the perspective of Skopos theory,taking Sun Zhongxu's translation work as an example,in which,literature method and case study method are adopted.The paper finds that Sun Zhongxu uses many colloquial expressions to convey the meaning of the source language.His translation strategies,his translation of American slangs,and his choices of words all reflect the three rules of Skopos theory.

典型高含硫气井分离器低效分离问题探究

天然气气井在开发生产后期的过程中,通常伴随气田水、细小颗粒等产出,采用分离装置进行初处理,由于分离装置中各相不可能实现完全分离,分离效果不佳,进而对下游装置平稳运行产生不利影响,并可能造成严重经济损失。通过现场试验分析某高含硫气井分离器低效率分离的现象,发现了分离器进气口流速增大,无足够稳定空间,内部液滴夹带严重,分离效果差的问题。提出了高含硫气井分离器低效分离问题的解决措施:正确选用入口元件并校核入口管嘴动压能;采用Ishii-Grolmes准则估算卧式气液分离器气相初始夹带速度;校核捕雾器的安装要求及淹没点(flooding point);选用可拆卸型内构件,设置内构件压差监测、建立定期清洗作业规程;井口一级气液分离器也可不配置捕雾器,简化设计,减少维护工作量。以上措施对高含硫气井分离器的设计、生产过程管理有一定指导意义。

钠冷快堆堆芯捕集器设计优化数值研究

堆芯捕集器是为有效分散堆芯熔融物并防止压力容器下封头与熔体大规模接触而被破坏的非能动预防和缓解装置。在钠冷快堆(SFR)中,堆芯捕集器的结构直接影响碎片床的堆积形状和分布,进而影响碎片床的再临界性和长期衰变热去除能力。本文针对堆芯捕集器的结构设计优化开展数值研究,重点关注其烟囱结构设计对碎片床形成和分布的影响机理及规律。基于无量纲刚度系数和无量纲阻尼系数改进离散元法(DEM),通过改变堆芯捕集器烟囱顶盖垂直投影边长、顶盖倾斜角度和烟囱间距,研究碎片颗粒的运动和碎片床的形成行为。结果表明,堆芯捕集器的烟囱顶盖垂直投影边长、烟囱顶盖倾角和烟囱间距对碎片床的堆积形状和分布均有重要影响,碎片颗粒的二次散射对于改善碎片床的均匀性至关重要。

福建某高岭土伴生石英提纯试验研究

以福建某高岭土伴生石英为研究对象,采用X射线衍射仪(XRD)和X射线荧光光谱仪(XRF)检测矿样的物相组成和化学成分,然后依次进行擦洗、磁选、浮选、分级-分选条件试验,结果表明:试样中SiO_(2)质量分数较低,为85.16%;石英主要以两种形式存在,一种是单体,另一种存在于岩屑中,与长石、云母等共生;浮选试验结果显示捕收剂用量和浮选浓度对降低Al_(2)O_(3)含量影响较大;分级-分选试验揭示了在相同工艺条件下,+0.6 mm粒级石英精矿中杂质含量远低于-0.6+0.1 mm粒级的石英精矿;最终获得的精矿中杂质Al_(2)O_(3)质量分数为2918.68μg/g,Fe_(2)O_(3)质量分数为63.53μg/g,达到了光伏发电玻璃面板所用石英砂的质量要求。

硫铵捕雾器阻力升高的解决方法

针对饱和器脱氨后煤气主管的捕雾器阻力升高,影响煤气系统正常运行的问题,增设煤气旁通管,拆除原煤气主管上的捕雾器,分别在2台饱和器出口管道上安装新的捕雾器。改造后如果捕雾器阻力升高时就可以切换饱和器,并进行饱和器离线检修。

Field synergy analysis of pollutant dispersion in street canyons and its optimization by adding wind catchers

The microenvironment,which involves pollutant dispersion of the urban street canyon,is critical to the health of pedestrians and residents.The objectives of this work are twofold:(i)to effectively assess the pollutant dispersion process based on a theory and(ii)to adopt an appropriate stratigy,i.e.,wind catcher,to alleviate the pollution in the street canyons.Pollutant dispersion in street canyons is essentially a convective mass transfer process.Because the convective heat transfer process and the mass transfer process are physically similar and the applicability of field synergy theory to turbulence has been verified in the literature,we apply the field synergy theory to the study of pollutant dispersion in street canyons.In this paper,a computational fluid dynamics(CFD)simulation is conducted to investigate the effects of wind catcher,wind speed and the geometry of the street canyons on pollutant dispersion.According to the field synergy theory,Sherwood number and field synergy number are used to quantitatively evaluate the wind catcher and wind speed on the diffusion of pollutants in asymmetric street canyons.The results show that adding wind catchers can significantly improve the air quality of the step-down street canyon and reduce the average pollutant concentrations in the street canyon by 75%.Higher wind speed enhances diffusion of pollutants differently in different geometric street canyons.

《麦田里的守望者》的青春书写及成长叙事

《麦田里的守望者》是塞林格的经典小说,小说讲述了一个青春期少年的内心挣扎和成长历程。故事围绕霍尔顿的内心独白展开,通过逃避责任、寻找自我身份等系列书写,向读者展示了特定时代背景下青年内心的纠结和迷茫,而这正是每个个体成长的必经之路。本文深度聚焦《麦田里的守望者》的青春书写及成长叙事,围绕守望者的叛逆、守望者的彷徨、守望者的救赎三个维度进行研究,深度解析主人公根植于时代的心路变革、迷茫簇拥下的流浪之旅、回归内心探寻生命意义的成长历程。