爱迪尔散热风扇继电器失效探析及改进

爱迪尔汽车在零部件国产化初期,售后市场出现批量散热风扇继电器失效故障。本文剖析故障原因,并对故障部件进行改进优化。     

Transport of radionuclides by sea-ice and dense-water formed in western Kara Sea flaw leads

A transport assessment of particle-bound and dissolved artificial radionuclides (¹³⁷Cs and ^239,240Pu) by sea-ice and dense-water formed in western Kara Sea flaw leads close to the Novaya Zemlya dumping sites is presented in this study. We both performed a “best estimate” based on available data, and a “maximum assessment” relying on simulated constant releases of 1 TBq ¹³⁷Cs and ^239,240Pu from individual dumping bays. The estimates are based on a combination of (i) the content of particulate matter in sea-ice; (ii) analytical data and numerical simulations of radionuclide concentrations in shelf surface deposits, suspended particulate matter (SPM), and the dissolved phase; and (iii) estimates of lead-ice and dense-water formation rates as well as modeling results of local ice drift pathways. In the “best estimate” case, 2.90 GBq ¹³⁷Cs and 0.51 GBq ^239,240Pu attached to sea-ice sediments can be exported from the lead areas toward the central Arctic basin. The radionuclide burden of the annually formed dense lead water in the “best estimate” amounts to 4.68 TBq ¹³⁷Cs and 0.014 TBq ^239,240Pu. In the “maximum assessment”, potential export-rates of ice-particle bound ¹³⁷Cs and ^239,240Pu toward the central Arctic would amount to 0.64 and 0.16 TBq, respectively. As much as ≈900 TBq ¹³⁷Cs and ≈6.75 TBq ^239,240Pu could be annually taken up by 34.75 dense-water rejected in the lead area. Assuming the (unlikely) instantaneous release of the total ¹³⁷Cs and ^239,240Pu inventories (≈1 PBq and 10 TBq, respectively) from the Novaya Zemlya dumping sites into the dissolved phase, the dense lead water locally formed during one winter season could take up ≈90% of the Cs and ≈68% of the Pu released.     

基于热化学轴对称烧蚀的仿真

基于烧蚀理论与计算机语言设计了固体火箭喷管烧蚀软件的主程序及系统框架.火箭喷管烧蚀是在高温高压冲刷氧化气流作用下发生的,利用极端环境下的热化学烧蚀模型,通过Fortran编程对喷管内热流场及烧蚀进行数值计算,并结合Matlab与VC＋＋自身的特点,采用混合编程技术实现火箭烧蚀软件的前后处理.由算例可知,该软件能够对喷管烧蚀进行仿真,并能够脱离编译环境在Windows平台上使用,使初始参数输入界面化,数值解图形化.     

基于CPⅢ的动态精确定位技术的应用与探讨

动态精确定位是综合检测列车的关键技术之一,其难点在于校准点对应的精确里程数据库的建立。本文利用目前高速铁路沿线布设的CPⅢ数据资源,采用简单的圆心测量与等分测量方法和数据处理软件,将校准点的里程与CPⅢ测量里程一一对应,建立精确数据库,从而实现了动态精确定位;并在京沪高速铁路K718—K740进行了最高速度为400 km/h的验证试验,动态定位精度可达1 m以内。     

射频消融术治疗室上性心动过速40例次分析

用射频消融术治疗室上性心动过速４０例次，共３４例（其中６例行消融术两次）。２７例消融成功（７９％），其中房室结折返性心动过速（ＡＶＮＲＴ）４例消融均成功（１００％），１例自律性房性心动过速（ＡＡＴ）消融房室结成功。房室折返性心动过速（ＡＶＲＴ）２９例，２２例旁路被阻断（７６％）。比较早期２０例次和后期２０例次消融术，结果显示早期消融术成功率（４０％）低于后期（１００％）（Ｐ＜０．０１），且早期手术时间［（６．８±２．５）ｈ］和放电次数［（１６．１±１０．５）次］均明显大于后期消融术［（２．８±１．２）ｈ，（４．６±２．５）次］（Ｐ＜０．０１）。作者讨论了失败的原因和成功的经验，表明操作者的经验与成功率密切相关。     

射频热凝靶点消融术在颈腰椎间盘突出症中的应用

目的观察射频热凝靶点消融术在治疗颈腰椎间盘突出症中的疗效及安全性,并对该新技术的推广应用做出评估。方法对120例经CT或MRI检查确诊的颈腰椎间盘突出症患者,根据临床症状、CT或MRI结果确定射频热凝的靶点位置,在C型臂引导下穿刺到靶点,通过椎间盘造影确定电极已进入靶点,再行阻抗测试、电生理测试及温度测试后,给予86-94℃温度,对靶点进行热凝消融。此时,通常可以复制出原有的腰腿痛症状,用此温度治疗4个周期,每个周期100 s。结果本组120例患者,经过该技术治疗后,其中73例治疗效果达优级,30例治疗效果良好,13例效果较差,4例无效,优良率85.8%。有4例患者术后并发轻微头痛、头晕等不适症状,均于2日内消失。余无其他并发症。结论射频热凝靶点消融术是目前治疗腰椎间盘突出症的最新的、且安全有效的方法。     

一例船用柴油机气门烧蚀故障的分析与处理

介绍B&W-6 L90 GBE船用柴油机排气门烧蚀的现象和故障排查过程,分析认为,装配的喷油泵柱塞偶件尺寸错误是造成气门烧蚀事故的根本原因,应加强对备件的管理和使用。     

心腔导管电消融治疗顽固性室上性心动过速

对17例抗心动过速药物治疗无效的顽固性室上性心动过速的患者,经使用心内导管电消融房室交界区,采取R波同步放电200～400J电能2～1次后,其中4例在电消融术后未安置长期心脏起搏器,另13例电消融术后形成完全性房室传导阻滞,安置了长期性心胜起搏器。临床实践证实了使用心腔导管电消融术对治疗顽固性室上性心动过速,可收到较好的效果。     

AN EFFICIENT RF COIL FOR GENERATING A CIRCULAR POLARIZED MAGNETIC FIELD

1IntroductionThecreationoftheprincipleofmagneticresonanceimage(MRI)iscreditedtoP.C.Lauterburwhoachivedthefirstimageinl973-It'hasbeendemonstratedthatMRIisabletopro-videthehumanbody'simagewithhighspatialresolutionandhighsensitivitytopathologicalchanges.TheRFcoilisusedtoproduceanddetectradiofrequency(RF)magneticfieldB,.IntheMRIsystemnuclearmagneticresonanceisexcit-edinabodytobeimagedbyapplyingtothebodyanRFmagneticfieldB,perpendiculartoarelativelystrongstaticmagneticfieldB,'IftheRFstreng…     

半月神经节射频热凝温控术治疗原发性三叉神经痛

目的 观察和分析射频热凝术治疗原发性三叉神经痛的临床疗效及并发症.方法 在DSA或C型臂引导下,采用Hartel前入路法,穿刺三叉神经半月节后以温控射频热凝对靶点毁损,温度控制在76～80 ℃,持续时间1～2 min,共3～4次.结果 本组56例中,53例术后疼痛完全消失,为Ⅰ级,视为临床治愈,治愈率为94.6%;1例达Ⅱ级明显缓解;1例达Ⅲ级;1例为Ⅳ级无效.治疗优良率为96.4%,总有效率为98.2%.无严重并发症.结论 射频热凝术是治疗原发性三叉神经痛安全可靠及有效的一种微创治疗技术.