Tao,An et al, Periodic radio variabilities in NRAO 530 a jet-disc connection 2013,MNRAS,438,900
阐述心房颤动听诊特点
阐述心房颤动听诊特点
心房颤动（Atrial Fibrillation，简称AF）是一种心律失常，通常表现为心房的不规则而迅速的收缩，导致心脏搏动不协调。
心房颤动的听诊特点是医生通过听诊患者心脏区域可以观察到一系列独特的体征和声音。
无规律的心跳：
在心房颤动时，心脏的搏动变得非常不规律。
正常的心跳是有规律的，而在心房颤动中，心脏的搏动失去了正常的节奏，呈现出混乱的状态。
快速而不规则的脉搏：
医生通过测量患者的脉搏可以感觉到心房颤动的存在。
患者的脉搏通常会呈现出快速而不规则的特点，这是由于心房的不协调性导致心室搏动的不规则性。
心音变化：
听诊时，医生可以观察到心音的变化。
典型的心音有两个部分：第一部分是心脏收缩时产生的"Lub"声，第二部分是心脏舒张时产生的"Dub"声。
在心房颤动中，这两个部分的节奏性会受到影响，听起
来可能像是不规律的"lub-dub"声。
心房扑动可能转变为心房颤动：
在某些情况下，心房扑动（Atrial Flutter）可能转变为心房颤动。
心房扑动是另一种心律失常，但与心房颤动相比，其心房搏动呈现出规律的振荡。
在听诊时，医生可以观察到不同的心音模式，有助于区分两者。
可能伴有其他心脏杂音：
由于心房颤动可能与其他心脏问题同时存在，例如心脏瓣膜病变，听诊时可能会出现与心房颤动有关的其他心脏杂音。
总体而言，心房颤动的听诊特点主要体现在心跳的不规律性、脉搏的快速和不规则，以及心音的变化。
这些特点有助于医生初步判断患者是否患有心房颤动，进而进行必要的检查和治疗。
代偿间歇的概念解释
代偿间歇的概念解释代偿间歇是一个医学术语，主要用于描述心电图上的一种现象。
当心脏出现期前收缩时，正常的窦性搏动被替代，导致在期前收缩后出现一个较长的心室舒张期，这就是代偿间歇。
代偿间歇可以分为完全性和不完全性两种类型，根据期前收缩的来源和影响不同。
代偿间歇的出现反映了心脏的自身调节能力，但也可能是一些心脏病的表现。
本文将介绍代偿间歇的定义、分类、机制、临床意义。
一、定义代偿间歇（Compensatory pause）是指在一次期前收缩（Premature contraction）之后，出现的一个较正常情况更长的心室舒张期（Ventricular diastole）。
期前收缩是指心脏在正常窦性节律（Sinus rhythm）之外，提前发生的一次异常收缩。
期前收缩可以发生在心房（Atrial premature contraction），心室（Ventricular premature contraction）或房室交界处（Atrioventricular junctional premature contraction）。
二、分类根据期前收缩是否影响窦房结（Sinoatrial node）的节律，代偿间歇可以分为完全性代偿间歇（Complete compensatory pause）和不完全性代偿间歇（Incomplete compensatory pause）。
2.1 完全性代偿间歇完全性代偿间歇是指在一次期前收缩之后，窦房结的节律没有受到影响，继续按照原来的频率发放冲动。
因此，在期前收缩之后，必须等到下一次窦房结冲动到达心室才能引起心室收缩。
这样，在期前收缩之后就会出现一个较长的心室舒张期，其长度等于两个正常窦性PP间期（PP interval）的总和减去一个期前收缩PQ间期（PQ interval）。
完全性代偿间歇通常见于室性期前收缩或房室交界处期前收缩。
2.2 不完全性代偿间歇不完全性代偿间歇是一种心律失常的现象，它发生在心房或心室提前收缩的情况下。
NovaSure 电磁波内膜消化术日志书说明书
Radio Frequency Endometrial AblationSurname: Forename:This log book has been designed specifically by Hologic to clearly identify your training needs and track progress. It aims to record experience, understanding and competence of the NovaSure® endometrial ablation system.The log book has 2 main sections:1. Theory: Most topics will be covered in the theoretical Training Day. When you have addressed each subjectin your reading and tutorials, and feel confident about it, then insert the date in the relevant box.2. Practical: Levels 1-4 represents the expected levels of competence and are to be interpreted as follows:Level 1:Observe NovaSure® being carried outLevel 2:Carry out a NovaSure® under direct supervision (your trainer is present throughout)Level 3:Carry out a NovaSure® under indirect supervision (your trainer need not be scrubbed,but should be immediately available for help and advice)Level 4:Independent competence - no supervision neededPractical training should be undertaken at your own hospital with your trainer. Hologic suggests that you undertake:•3 observed cases to meet Level 1 criteria•5 cases managed under direct supervision to meet Level 2 criteria•5 cases managed under indirect supervision to meet Level 3 criteria•5 cases that you have managed independently to meet Level 4 criteriaThere is also an OSATS for performing NovaSure® – please complete regularly to demonstrate progression of training.Additional CasesAdditional CasesAdditional CasesI can confirm that my trainee is now competent to undertake NovaSure ® independently.I can confirm that is now competent to undertake NovaSure ® independently.Title:Hospital/Facility:Trainer:Signature:Date:Signature:Date:Name:Title:Assessor, please tick the candidate’s performance for each of the following factors:Based on the checklist and the Generic Technical Skills Assessment, Dris competent in all areas included in this OSATS is working towards competenceNeeds further help with:Competent to perform the entire procedure without the need for supervisionSigned:Signed:Date:Signed (trainer): Signed (trainee): Date:Self-Verification of competence is undertaken by assessment against the following statements:These statements are designed to indicate competence to use this item. Responsibility for the use remains with the user, so if you are in any doubt regarding your competence to use the item, you should seek education to bring about improvement. Various methods including self-directed learning, coaching and formal training may be initiated (consider local resources, product operating manual, discussion with colleagues or the appropriate key person in your area).Carry out an initial assessment. Y ou must answer yes to all questions before considering yourself to be competent.If you are not competent, instigate learning and then repeat assessment.I certify that I am aware of my professional responsibility for continuing professional development and I realise that I am accountable for my actions. With this in mind I make the following statement:I require further training before I can use this product in a competent mannerI am competent to use this product without further training:Date:Date:Signature:Signature:Indicate how you plan to meet your learning needs:Keep this form in your personal portfolio or training record. Ensure that your Manager receives a copy of the form and enters details of your competence in their records.Statement©2021 Hologic, Inc. Hologic, The Science of Sure, NovaSure and associated logos are trademarks or registered trademarks of Hologic, Inc. and/or its subsidiaries in the United States and/or other countries. This information is intended for medical professionals and is not intended as a product solicitation or promotion where such activities are prohibited. Because Hologic materials are distributed through websites, eBroadcasts and tradeshows, it is not always possible to control where such materials appear. Forspecificinformationonwhatproductsareavailableforsaleinaparticularcountry,**********************************************************************。
心房颤动的基因治疗研究进展
簸二÷霹攀蕤缓菰ＤＮＡ疼毒，奎径１９～戆Ｅｔｍ，ＡＡＶ舞ｒｅｐ
秘ｃａｐ基阑组成，并崴被终端骡Ｐ环绕。应糯于基裰治疗， 这两个撼因都可以被删除，留下ＩＴＰ包裹目的基因插入。蹦 熬，转基因治疗使弼艨癜毒及艨瘸毒微赖鹣裁髂转运基戮淡 减少免疫葳瘟，圊露它《默提裔对徽搬黪静渗透往，趱薅麓 爨转染鹩均匀性翻肖羧性¨“。 过去凡年，通避瘸毒载体终｛奉内心驻转基西秘渗疗穗 不凝褥麓证实。心臌憋基因转导主要有三释方法：冠袄瓣黥 （篱称冠脉）灌注法；心肌直接淀射法；经心瓤基因涂染转臀 法。Ｄｏｎａｈｕｅ等”酬掇遵了嚣爨瀵注法，郄主璐艨黎黪凌艨交 叉辫夹技术，这一方法是将导誊撬入左塞心尖，遥遵警管注 射商浓魔腺病毒，同时用另一根特制的导管在心导管的避 端交叉钳夹主、肺动脉ｌＯ～４０ ｓ。通过交叉钳夹主、肺动脉，
section B
1.常用的β受体阻滞剂
阿替洛尔(又叫氨酰心安)
美托洛尔(商品名倍他乐克)
盐酸索他洛尔
2.钙通道选择性阻滞药
维拉帕米、加洛帕米、噻帕米。
硝苯地平、尼卡地平、尼群地平、氨氯地平、尼莫地平、尼索地平。
地尔硫卓、克仑硫卓、二氯夫利。
氟桂利嗪、桂利嗪、利多氟嗪。
普尼拉明。
哌克昔林。
3.血管紧张素转换酶抑制剂（ACEI）
卡托普利、依那普利、西拉普利、奎那普利、雷米普利、苯那普利、培哚普利、螺普利、福辛普利。
4. 血管紧张素Ⅱ受体拮抗剂
氯沙坦、缬沙坦、厄贝沙坦、坎地沙坦酯及他索沙坦、依普罗沙坦及替米沙坦。
医学科普·临床症状知识文库：奔马律心音
相关疾病：
心律失常 心肌梗死 急性心肌梗死 新生儿心律失常 小儿心律失常 小儿致心律失常性右室心肌病 小儿窦性心律失常 窦性心律失常 老年心肌病 结节病步发展，当今医疗面对的 症状越来越多，为便于大家了解 掌握，本文收集整理了临床症状 奔马律心音的相关资料 以供大家参阅。 由于部分内容人类尚未掌握 或其他原因暂缺，敬请谅解。
奔马律心音
简介：正常成人心脏跳动有两个心音，称为第一心音和第二心 音，奔马律为出现在第二心音后的附加心音，与原有的第一、 第二心音组合而成的韵律，酷似马奔跑时马蹄触地发出的声 音，故称为奔马律。根据奔马律出现时间的不同，可分为舒张 早期奔马律，舒张晚期奔马律和重叠性奔马律，其中以舒张早 期奔马律最为常见，它出现在第二心音后0.12-0.18秒内;舒张晚 期奔马律发生较晚，出现在收缩期开始之前，即第一心音前 0.1秒，故也称收缩期奔马律;当同时存在舒张早期奔马律和舒 张晚期奔马律时，加上第一心音和第二心音，听起来就象平行 发生的四个音响，又称“四音律”，“火车头奔马律”。一般认为 舒张早期奔马律是由于心室舒张期负荷过重，心肌张力减低与 顺应性减退，以致心室舒张时，血液充盈引起室壁震动。所以 奔马律的出现是心肌严重受损的重要体征。
病因： 奔马律是由于心室舒张期负荷过重，心肌张力减低与顺应 性减退，以致心室舒张时，血液充盈引起室壁震动。所以奔马 律的出现是心肌严重受损的重要体征。
诊断： 是心脏病症状的一种，需与其他症状一起联合诊断。风湿 性二尖瓣炎风湿性二尖瓣狭窄、感染性心内膜炎、类风湿性心 脏病系统性红斑狼疮、主动脉瓣关闭不全的Austin-Flint 杂音、 左房部液瘤二尖瓣较大的赘生物或血栓、缩窄性心包炎、 Hurler综合征动脉导管未闭、Lutembacher综合征、重度二尖瓣 关闭不全重度主动脉瓣关闭不全、分流量大的室间隔缺损、高 血压性心脏病主动脉缩窄、扩张性心肌病、贫血性心脏病甲状 腺功能亢进性心脏病、三度房室传导阻滞。其他原因所致的心 尖区舒张期杂音。
心理学专业考研重点名词中英文对照表（七）
频率——frequency 振幅——amplitude ⾳频——pitch 基⾳——fundamental tone 倍⾳——overtone 和谐⾳——harmonic ⾳⾊——timbre ⽩⾊噪⾳——white noise ⿎膜——eardrum ⽿蜗——cochlea 卵形窗—oval window 圆形窗——round window 前庭——vestibular sacs 半规管——semicircular canals ⾓膜——cornea ⽔晶体——lens 虹膜——iris 瞳孔——pupil 膜——retina 睫状肌——ciliary muscle 调节作⽤——accommodation 脊髓——spinal cord 反射弧——reflex arc 脑⼲——brain stem 计算机轴性线断层扫描——CAT或CT PET——正⼦放射断层摄影 MRI——磁共振显影 延脑——medulla 桥脑——pons ⼩脑——cerebellum 状结构——reticular formation RAS——状活化系统 视丘——thalamus 下视丘——hypothalamus ⼤脑——cerebrum 脑（下）垂体（腺）—pituitary gland 脑半球——cerebral hemisphere ⽪质——cortex 胼胝体——corpus callosum 边缘系统——limbic system 海马体——hippocampus 杏仁核——amygdala 中央沟——central fissure 侧沟——lateral fissure 脑叶——lobe 同卵双⽣⼦——identical twins 异卵双⽣⼦—fraternal twins 古典制约——classical conditioning 操作制约——operant conditioning ⾮制约刺激—（US unconditioned stimulus ⾮制约反应—（UR）unconditioned R. 制约刺激——（CS）conditioned S. 制约反应——（CR）conditioned R. 习（获）得——acquisition 增强作⽤——reinforcement 消除（弱）——extinction ⾃（发性）然恢复——spontaneous recovery 前⾏制约—forward conditioning 同时制约——simultaneous conditioning 回溯制约——backward cond. 痕迹制约——trace conditioning 延宕制约—delay conditioning 类化（梯度）——generalization（gradient） 区辨——discrimination （次级）增强物——（secondary）reinforcer 嫌恶刺激——aversive stimulus 试误学习——trial and error learning 效果率——law of effect 正（负）性增强物—positive（negative）rei. ⾏为塑造—behavior shaping 循序渐进——successive approximation ⾃⾏塑造—autoshaping 部分（连续）增强—partial（continuous）R 定⽐（时）时制—fixed ratio（interval）schedule FR或FI 变化⽐率（时距）时制—variable ratio（interval）schedule VR或VI 逃离反应——escape R. 回避反应—avoidance response 习得⽆助——learned helplessness 顿悟——insight 学习⼼向—learning set 隐内（潜在）学习——latent learning 认知地图——cognitive map ⽣理回馈——biofeedback 敏感递减法-systematic desensitization 普⾥迈克原则—Premack''''s principle 洪⽔法——flooding 观察学习——observational learning 动物⾏为学——ethology 敏感化—sensitization 习惯化——habituation 联结——association 认知学习——cognitional L. 观察学习——observational L. 登录﹑编码——encoding 保留﹑储存——retention 提取——retrieval 回忆——（free recall 全现⼼像﹑照相式记忆——eidetic imagery﹑photographic memory . ⾆尖现象（TOT）—tip of tongue 再认——recognition 再学习——relearning。
心内科医学专业英语词汇
心力衰竭(heart failure)心功能不全或心功能障碍(cardiac dysfunction)Systolic insufficiency heart failure 收缩功能不全性心力衰竭[si'stɔlik］Diastolic insufficiency heart failure 舒张功能不全性心力衰daiə’stɔlik] Congestive heart failure 充血性心力衰竭急性心力衰竭（acute heart failure,AHF)Acute left-sided heart failure 急性左心衰竭慢性心力衰竭(chronic heart failure，CHF）Intractable heart failure 难治性心力衰竭心律失常（cardiac arrhythmia)窦性心动过速（sinus tachycardia）窦性心动过缓(sinus bradycardia)窦性停搏或窦性静止(sinus pause or sinus arrest)窦房传导阻滞（sinoatrial block，SAB，窦房阻滞）病态窦房结综合征（sick sinus syndrome,SSS，简称病窦综合征）心动过缓一心动过速综合征(bradycardia—tachycardia syndrome)房性期前收缩（atrial premature beats)房性心动过速（atrial tachycardia）紊乱性房性心动过速（chaotic atrial tachycardia）=多源性房性心动过速（multifocal atrial tachycardia）自律性房性心动过速（automatic atrial tachycardia）折返性房性心动过速（reentrant atrial tachycardia)房室阻滞的阵发性房性心动过速（paroxysmal atrial tachycardia with A V block, PAT with block）心房扑动(atrial flutter）心房颤动(atrial fibrillation)房室交界区性期前收缩(premature atrioventicular junctional beats)房室交界区性逸搏（A V junctional escape beats)房室交界区性心律(A V junctional rhythm)非阵发性房室交界区性心动过速（nonparoxysmal atrioventricular junctional tachycardia）阵发性室上性心动过速（paroxysmal supraventricular tachycardia，PSVT)房室结内折返性心动过速(atrioventricular nodal reentrant tachycardia,A VNRT）利用隐匿性房室旁路的房室折返性心动过速(atrioventricular reentrant tachycardia，A VRT）预激综合征(preexcitation syndrome)Wolf—Parkinson-White综合征(WPW综合征)室性期前收缩（premature ventricular beats)室性并行心律（ventricular parasystole）Systole n. 心脏收缩室性心动过速（ventricular tachycardia）加速性心室自主节律(accelerated idioventricular rhythm）亦称缓慢型室速尖端扭转(torsades de pointes）心室扑动与颤动(ventricular flutter and ventricular fibrillation）房室传导阻滞（atrioventricular block)室内传导阻滞（intraventricular block）右束支阻滞(right bundle branch block,RBBB)左束支阻滞(left bundle branch block，LBBB）左前分支阻滞（left anterior fascicular block)左后分支阻滞（left posterior fascicular block)双分支阻滞与三分支阻滞(bifaseicular block and trifascicular block）心脏骤停(cardiac arrest）心脏性猝死(sudden cardiac death)无脉性电活动(pulseless electrical activity，PEA）=电—机械分离(electromechanical dissociation，EMD)先天性心血管病（congenital cardiovascular diseases）房间隔缺损（atrial septal defect，ASD)室间隔缺损（ventricular septal defect，VSD)动脉导管未闭(patent ductus arteriosus，PDA)先天性二叶主动脉瓣(congenital bicuspid aortic valve)先天性肺动脉瓣狭窄(congenital pulmonary valve stenosis)先天性三尖瓣下移畸形多称之为埃勃斯坦畸形( Ebstein anomaly) 先天性法洛四联症(congenital tetralogy of Fallot）艾森门格综合征(Eisenmenger syndrome)原发性高血压(primary hypertension)Secondary hypertension 继发性高血压Hypertensive crisis 高血压危象Hypertensive urgencyes 高血压急症Hypertensive emergencies 高血压危症Isolated systolic hypertension 单纯收缩期高血压平均动脉血压(MBP Mean arterial blood pressure）收缩压(SBP Systolic blood pressure）舒张压(DBP Diastolic blood pressure )动脉粥样硬化(atherosclerosis)动脉粥样硬化—血栓形成(atherosclerosis-thrombosis)冠状动脉性心脏病(coronary heart disease）=缺血性心脏病(ischemic heart disease）冠状动脉粥样硬化性心脏病(coronary atherosclerotic heart disease）急性冠脉综合征( acute coronary syndrome，ACS）不稳定型心绞痛(unstable angina，UA）非ST段抬高性心肌梗死(non—ST—segment elevation myocardial infarction，NSTEMI）ST段抬高性心肌梗死（ST—segment elevation myocardial infarction,STEMI）慢性冠脉病(chronic coronary artery disease，CAD=慢性缺血综合征chronic ischemic syndrome，CIS）稳定型心绞痛（stable angina pectoris）无症状性心肌缺血Cardiovascular neAsymptomatic myocardial ischemia缺血性心肌病Ischemic cardiomyopathy乳头肌功能失调或断裂(dysfunction or rupture of papillary muscle)心脏破裂（rupture of the heart)栓塞（embolism）心室壁瘤（cardiac aneurysm)心肌梗死后综合征（postinfarction syndrome)经皮冠状动脉介入（percutaneous coronary intervention，PCI）二尖瓣狭窄(mitral stenosis）主动脉瓣狭窄(aortic stenosis)二尖瓣关闭不全(mitral incompetence)Acute mitral incompetence 急性二尖瓣关闭不全Chronic mitral incompetence 慢性二尖瓣关闭不全主动脉瓣关闭不全（aortic incompetence)三尖瓣狭窄( tricuspid stenosis)三尖瓣关闭不全(tricuspid incompetence)肺动脉瓣关闭不全（pulmonary incompetence）肺动脉瓣狭窄(pulmonary stenosis)感染性心内膜炎(infective endocarditis，IE)endocarditics（AIE）急性感染性心内膜炎Subacute Infective endocarditis 亚急性感染性心内膜炎自体瓣膜心内膜炎（native valve endocarditis）Prothetic（[,prɔ’θetik］)valve endocarditis 人工瓣膜心内膜炎（修复的）Endocarditis in intravenous drug abusers 静脉药瘾者心内膜炎扩张型心肌病(dilated cardiomyopathy,DCM)肥厚型心肌病(hypertrophic cardiomyopathy，HCM)致心律失常型右室心肌病(arrhythmogenic right ventricular cardiomyopathy，ARVC)旧称为致心律失常右室发育不良(arrhythmogenic right ventricular dysplasia，ARVD)不定型的心肌病( unclassified cardiomyopathies,UCM）特异性心肌病（specific cardiomyopathies）心肌炎(myocarditis）Purulent pericarditis 化脓性心包炎Acute pericarditis 急性心包炎Tuberculous pericarditis 结核性心包炎Constrictive pericarditis 缩窄性心包炎cardiac tamponade心脏压塞；心包填塞；[，tæmpə'neidpericardial tamponade心包压塞［,peri'kɑ:diəl，pericardial constriction心包缩窄Aortic dissection 主动脉夹层左室舒张末压LVEDP (left ventricular end-diastolic pressure)肺毛细血管楔压PCWP（pulmonary capillary wedge pressure）心脏指数CI(Cardiac index）主动脉内球囊反搏IABP(intra-aortic ballon pump）血管紧张素Ⅱ(angiotensinⅡ，AⅡ）心脏重塑(Cardiac remodeling)心钠肽和脑钠肽（atrial natriuretic peptide，ANP and brain natriuretic peptide，BNP)重组人BNP（Recombinant human BNP rhBNP)奈西立肽（Nesiritide)精氨酸加压素（arginine vasopressin，A VP）心房牵张受体(atrialstretch receptors）内皮素(endothelin)阿米洛利（amiloride)卡托普利(captopril）贝那普利(benazepril）培哚普利(perindopril)坎地沙坦（candesatan）、氯沙坦(losartan)、缬沙坦（valsartan）卡维地洛(carvedilol）、比索洛尔(bisoprolol)、艾司洛尔［esmolol]地高辛（digoxin)、洋地黄毒苷（digitoxin)及毛花苷C （lanatoside C，西地兰）、毒毛花苷K（strophanthin K)肼苯达嗪（hydralazine）、硝酸异山梨酯（isosorbidedinitrate）心脏再同步化治疗(cardiac resynchronization therapy,CRT）触发活动( triggered activity）后除极(after depolarization)窦房结恢复时间（sinus node recovery time，SNRT)校正的窦房结恢复时间（corrected SNRT，CSNRT）窦房传导时间(sinoatrial conduction time,SACT）巨大a波（canon wave)动态心电图(Holter ECG monitoring）PA（反映心房内传导）、AH（反映房室结传导)、HV(反映希氏束—普肯耶系统传导)Adams—Stokes(阿斯）综合征莫氏（Mobitz）Ⅰ型即文氏（Wenckebach）阻滞固有心率(intrinsic heart rate,IHR)凝血酶原时间国际标准化比值(INR)房室旁路（accessoryat riovcntricular pathways）或Kent束房-希氏束( atriohisian tracts)结室纤维(nodoventricular fibers)分支室纤维（fasciculoventricular fibers)心肺复苏（Cardiopulmonary resuscitation，CPR）急救医疗系统(emergency medical system, EMS）基础生命活动支持（basic life support,BLS）ABC （airway,breathing，circulation)埋藏式心脏复律除颤器(implantable cardioverter defibrillator，ICD）Cardiogenic shock 心源性休克Pulmonary embolism 肺动脉栓塞Syncope 晕厥［’siŋkəp，'sin-］尿激酶( urokinase，UK)链激酶(streptokinase，SK）或重组链激酶（rSK)重组组织型纤维蛋白溶酶原激活剂（recombinant tissue—type plasminogen activator，rt—PA) 1A。
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1 I N T RO D U C T I O N The energy release in an active galactic nucleus (AGN) remains the most fundamental issue in extragalactic astrophysical studies. Powered by accretion of gas on to the central supermassive black hole (SMBH), the extreme compactness of the AGN limits direct imaging of the central engines because of insufficient resolution of existing radio and infrared interferometers. On the other hand, the variability analysis of the continuum and emission line radiation contains a wealth of (indirect) information on the dynamical processes taking place in the heart of the active galaxies. For instance, the characteristic variability time-scale may place a constraint on the physical size of the emission zone and discriminate between processes governing the temporal variations. Blazars are a subclass of AGN characterized by rapid and violent variability at almost all spectral bands. These quasi-periodic fluctuations of luminosity may have a direct relationship with the physical processes occurring in the vicinity of an SMBH. A well-known example of the AGN with periodic variability is the BL Lac object OJ 287, which displays an ∼12-yr periodicity in the optical light curves and was thought ¨ et al. 1988, 1996b; to contain a binary black hole (BH; Sillanp¨ aa Lehto & Valtonen 1996).
Accepted 2013 July 9. Received 2013 July 9; in original form 2013 May 5
ABSTRACT
Time series analysis techniques, Lomb–Scargle periodogram and weighted wavelet Z-transform, have been employed to search for year-time-scale periodicities from the radio light curves of a typical blazar NRAO 530. The periodicity analysis using the two methods show consistent results: two strong and persistent periods of ∼10 and ∼6 yr are prominent at all three wavelengths; three other weaker periodicities with shorter time-scales (∼5, ∼3.5 and ∼3 yr) were also seen; in addition, the 14.5-GHz WWZ power spectrum revealed a ∼2-yr periodic component during the time interval 1983–1990. Statistical significance analysis suggests that these periodicities might result from physically periodic process. The characteristic frequencies of these periodicities seem to have a harmonic relationship, and the fundamental frequency, i.e. the first-order harmonic, is about 0.05 yr−1 (P0 = 20 yr). But the fundamental frequency was not pronounced. The multiplicity and apparent harmonic relationship of the periodicities could be interpreted by the global p-mode oscillation of the accretion disc, if the jet and disc are coupled. In this scenario, the periodic fluctuations in the accretion rate consequently lead to the observed periodic variabilities of the radio luminosity. Key words: methods: statistical – galaxies: active – quasars: individual: NRAO 530.
Tao An,1,2 ‹ Willem A. Baan,1 Jun-Yi Wang,3,4 ‹ Yu Wang1 and Xiao-Yu Hong1,2
1 Shomical Observatory, Chinese Academy of Sciences, 80 Nandan Road, 200030 Shanghai, China Laboratory of Radio Astronomy, Chinese Academy of Sciences, 210008 Nanjing, China 3 Key Laboratory of Cognitive Radio & Information Processing, the Ministry of Education, Guilin University of Electronic Technology, 541004 Guilin, China 4 School of Mathematics and Computing Science, Xiangtan University, 411105 Hunan, China
E-mail: antao@ (TA); wangjy@ (J-YW)
Traditional numerical methods searching for periodicities in time series have been mostly based on Fourier transform analysis (e.g. Deeming 1975; Lomb 1976; Ferraz-Mello 1981; Scargle 1982, 1989; Hufnagel & Bregman 1992; Hughes, Aller & Aller 1992). An improved Fourier-based technique of periodicity analysis, called a Lomb–Scargle (LS) periodogram, performs least-squares fitting to the time series of unevenly sampled data with a linear combination of trigonometric functions (Lomb 1976; Scargle 1982). Canonical Fourier transform searches for the periodicity over the whole time range using a fixed sinusoidal function. Such Fourier-based methods perform well when the periodicity parameters (period, amplitude and phase) remain constant over the whole time span. However, the flux density variations of astronomical objects often do not exhibit a strictly persistent period. The periodic variabilities of blazars are always blended with random fluctuations resulting from intermittent or short-lifetime outbursts. Therefore, the fit of sinusoidal functions to the whole time series often obscures any time evolution of the periodicities. In contrast to Fourier transform, the wavelet transform is remarkable for its localization ability in both time and frequency domains. A wavelet transform decomposes a time series by projecting the signal on to a set of trial wavelet functions that can have any shape and time duration. The time-localization property of the wavelet transform allows us to keep localized time-scales and trace the time evolutions of the period parameters (Grossman, Kronland-Martinet