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Source process of the 2010 Yushu,Qinghai,earthquake

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Science China Earth Sciences 2010年第9期53卷 1249-1251页

作者： Yong Zhang LiSheng Xu yun-tai Chen Institute of Geophysics China Earthquake Administration Beijing 100081 China

The comprehensive waveform analysis of the Love waves and P waves shows that the Yushu M S7.1 (M W6.9) earthquake consists of two distinct sub-events. The first one occurred in the first 5 s releasing less seismic moment, and the second occurred in the later 11 s releasing more seismic moment. Spatially, the first sub-event surrounded the hypocenter, and the second, about 30 km away from the first, was much closer to the Yushu city and broke through the ground surface. In terms of the rupture velocity to which the peak values of the two sub-events correspond, the first sub-event propagated with an average rupture velocity of 1.6 km/s, however, the second propagated with an average rupture velocity of 4.0 km/s which is actually superior to the shear-wave velocity in the hypocentral region. The magnitude of the Yushu earthquake is in the lower margin of large earthquakes. The results obtained in this study indicate that the super-shear rupture possibly appears in earthquakes with magnitude of around 7.0, instead of only in the great earthquakes with magnitude around 8.0 [14, 15]. In addition, the energy focusing caused by the super-shear rupture should take key responsibility for the tremendous damage to the Yushu city as well as the ground-surface breakage related to the larger second sub-event.

关键词： Velocity Wave propagation

Instability of OTSG in movable NPP by using multivariable frequency domain method

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Nuclear Science and Techniques 2010年第1期21卷 54-59页

作者： HOU Suxia tai yun ZHAO Fuyu WEI Xinyu Xi ＇an Jiaotong University Xi ＇an 710049 China The Second Artillery Engineering Institute Xi ＇an 710025 China

The instability occurring in OTSG (Once-Through Steam Generator) of movable nuclear power plants is presented by a multivariable frequency domain *** concerning coupling interactions of OTSG tubing,it is more efficient for analyzing the instability of OTSG compared the common single variable method.A mathematical model for the system is derived from the fundamental equations by using the perturbation,Laplace-transform and the nodalization *** stable boundary and parameters which influence the stability of the system are evaluated through computer *** examples are given in the paper and the predictions of the model agree with the experimental results well.

关键词：直流蒸汽发生器多变量频域法不稳定核电站拉普拉斯变换数学模型计算机模拟耦合作用

Relocation of the 1998 Zhangbei-Shangyi earthquake sequence using the double difference earthquake location algorithm

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Acta Seismologica Sinica(English Edition) 2004年第2期17卷 125-130页

作者： YANG Zhi-xian(杨智娴) CHEN yun-tai(陈运泰) Institute of Geophysics China Earthquake Administration Beijing 100081 China Institute of Geophysics China Earthquake Administration Beijing 100081 China

On January 10, 1998, at 11h50min Beijing Time (03h50min UTC), an earthquake of ML=6.2 occurred in the border region between the Zhangbei County and Shangyi County of Hebei Province. This earthquake is the most significant event to have occurred in northern China in the recent years. The earthquake-generating structure of this event was not clear due to no active fault capable of generating a moderate earthquake was found in the epicentral area, nor surface ruptures with any predominate orientation were observed, no distinct orientation of its aftershock distribution given by routine earthquake location was shown. To study the seismogenic structure of the Zhangbei- Shangyi earthquake, the main shock and its aftershocks with ML3.0 of the Zhangbei-Shangyi earthquake sequence were relocated by the authors of this paper in 2002 using the master event relative relocation technique. The relocated epicenter of the main shock was located at 41.145癗, 114.462癊, which was located 4 km to the NE of the macro-epicenter of this event. The relocated focal depth of the main shock was 15 km. Hypocenters of the aftershocks distributed in a nearly vertical plane striking 180~200 and its vicinity. The relocated results of the Zhangbei-Shangyi earthquake sequence clearly indicated that the seismogenic structure of this event was a NNE-SSW-striking fault with right-lateral and reverse slip. In this paper, a relocation of the Zhangbei-Shangyi earthquake sequence has been done using the double difference earthquake location algorithm (DD algorithm), and consistent results with that obtained by the master event technique were obtained. The relocated hypocenters of the main shock are located at 41.131癗, 114.456癊, which was located 2.5 km to the NE of the macro-epicenter of the main shock. The relocated focal depth of the main shock was 12.8 km. Hypocenters of the aftershocks also distributed in a nearly vertical N10E-striking plane and its vicinity. The relocated results using DD algorithm cl

关键词： Zhangbei-Shangyi earthquake double difference earthquake location algorithm earthquake relocation seismogenic structure source process

Sevoflurane Versus Propofol for Myocardial Protection in Patients Undergoing Coronary Artery Bypass Grafting Surgery: a Meta-analysis of Randomized Controlled Trials

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Chinese Medical Sciences Journal 2009年第3期24卷 133-141页

作者： yun-tai Yao Li-huan Li Department of Anesthesiology Fuwai Cardiovascular Hospital Chinese Academy of Medical Sciences ＆ Peking Union Medical College Beijing 100037 China

Objective To systematically review randomized controlled trials to compare myocardial protection profiles of sevoflurane with propofol in patients undergoing coronary artery bypass grafting （CABG） surgery. Methods Electronic databases were searched to identify all randomized controlled trials comparing sevoflurane with propofol for protecting myocardium in adult patients undergoing CABG surgery. Two authors independently extracted patients＇ perioperative data, including patients＇ baseline characteristics, surgical variables, and outcome data. For continuous variables, treatment effects were calculated as weighted mean difference （WMD） and 95% confidential interval （C/）. For dichotomous data, treatment effects were calculated as odds ratio （OR） and 95% CI. Each outcome was tested for heterogeneity, and randomized-effects or fixed-effects model was used in the presence or absence of significant heterogeneity （Q test P〈0.05）. Sensitivity analyses were done by examining the influence of statistical model on estimated treatment effects. Publication bias was explored through visual inspection of funnel plots of the outcomes. Statistical significance was defined as P〈0.05. Results Our search yielded 13 studies including 696 patients, and 402 patients were allocated into sevoflurane group and 294 into propofol group. There was no significant difference in postoperative mechanical ventilation time, inotropic support, mortality, myocardial infarction, and atrial fibrillation between the two groups （all P〉0.05）. Patients randomized into sevoflurane group had higher post-bypass cardiac index （WMD=0.39, 95% CI： 0.18 to 0.60, P=0.0003）, lower troponin I level （WMD=-0.82, 95% CI：-0.87 to -0.85, P=0.0002）, lower incidence of myocardial ischemia （OR=0.37, 95% CI： 0.16 to 0.83, P=0.02）, shorter ICU and hospital stay length （WMD=-10.99, 95% CI： -12.97 to -9.01, P〈0.00001; WMD=-0.78, 95% CI： -1.00 to -0.56, P〈0.00001, respectively）. Conclusion This meta-analysis has found some evide

关键词： sevoflurane propofol myocardial protection coronary artery bypass grafting meta-analysis

Downregulation of Na^＋/Ca^2＋ Exchanger Isoform 1 Protects Isolated Hearts by Sevoflurane Postconditioning but Not by Delayed Remote Ischemic Preconditioning in Rats

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Chinese Medical Journal 2017年第18期130卷 2226-2233页

作者： Yang Yu Cheng-Hui Zhou yun-tai Yao Li-Huan Li Department of Anesthesiology Fuwai Cardiovascular Hospital Beijing 100037 China

Background：Calcium regulatory proteins-L-type Ca^2＋ channels （LTCCs）,ryanodine receptor 2 （RyR2）,and Na^＋/Ca^2＋ exchanger isoform 1 （NCX1） have been recognized as important protective mechanisms during myocardial ischemia-reperfusion injury （I/RI）.Both sevofturane postconditioning （SevoPoC） and delayed remote ischemic preconditioning （DRIPC） have been shown to protect the heart against I/*** this study,we aimed to compare the effects of SevoPoC and DRIPC on the expression of the three calcium regulatory proteins in an isolated rat heart ***：After 30-min balanced perfusion,isolated hearts from rats were subjected to 30-min ischemia followed by 60-min *** 40 isolated hearts were randomly assigned to four groups （n =10/group）：time control group,I/RI group,SevoPoC group,and DRIPC *** effect of SevoPoC （3% v/v） and DRIPC were *** infarct size （IS）,cardiac troponin I level,and heart function were *** protein and messenger RNA levels of LTCCs,RyR2,and NCX1 were ***：Both SevoPoC and DRIPC improved the recovery of myocardial function,and reduced cardiac troponin Ⅰ release after I/*** decrease in IS was more significant in the SevoPoC group than that in the DRIPC group （16.50% ± 4.54% in the SevoPoC group [P =0.0006],and 22.34% ± 4.02% in the DRIPC group [P =0.0007] vs.35.00% ± 5.24% in the I/RI group,respectively）.SevoPoC,but not DRIPC significantly inhibited the activity of NCX 1 （0.59 ＋ 0.09 in the I/RI group vs.0.32 ± 0.16 in the SevoPoC group,P =0.006;vs.0.57 ± 0.14 in the DRIPC group,P =0.072）.No statistical significant differences were observed in the expression of LTCCs and RyR2 between SevoPoC and *** addition,subsequent correlation analysis showed a significantly positive relationship between the cardiac troponin Ⅰ level and the protein expression ofNCX1 （r =0.505,P =0.023）.Conclusion：SevoPoC may be more effective in the cardioprotection than DRIPC partly due to the deactivation of NCX

关键词： Calcium Regulatory Protein: Delayed Remote lschemic Preconditioning Ischemia-reperfusion Injury Na^+/Ca^2+ Exchanger Sevoflurane Postconditioning

Fast and robust inversion of earthquake source rupture process and its application to earthquake emergency response

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Earthquake Science 2012年第2期25卷 121-128页

作者： Yong Zhang yun-tai Chen Lisheng Xu Institute of Geophysics China Earthquake AdministrationBeijing 100081China

Fast inversion of source rupture process for significant earthquake is introduced and applied to earthquake emergency response. We retrieve and use the apparent source time functions （ASTFs） to stabilize the rupture process inversion, aiming to get the rupture process results correctly and quickly. The applications to 22 significant earthquakes occurred between January 2009 and July 2011 show an average inversion time consumed of about four hours, suggesting a high efficiency of this method, which much improves the inversion speed of the rupture process and is helpful in earthquake disaster mitigation and relief.

关键词： rupture process earthquake emergency disaster mitigation real time seismology

Rupture process of the 2011 Tohoku earthquake from the joint inversion of teleseismic and GPS data

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Earthquake Science 2012年第2期25卷 129-135页

作者： Yong Zhang Lisheng Xu yun-tai Chen Institute of Geophysics China Earthquake AdministrationBeijing 100081China

Teleseismic and GPS data were jointly inverted for the rupture process of the 2011 Tohoku earthquake. The inversion results show that it is a bilateral rupture event with an average rupture velocity less than 2.0 km/s along the fault strike direction. The source rupture process consists of three sub-events, the first oc- curred near the hypocenter and the rest two ruptured along the up-dip direction and broke the sea bed, causing a maximum slip of about 30 m. The large-scale sea bed breakage may account for the tremendous tsunami disaster which resulted in most of the death and missing in this mega earthquake.

关键词： 2011 Tohoku earthquake rupture process joint inversion teleseismic data GPS data

Sevoflurane postconditioning protects isolated rat hearts against ischemia-reperfusion injury

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Chinese Medical Journal 2010年第10期123卷 1320-1328页

作者： YAO yun-tai FANG Neng-xin SHI Chun-xia LI Li-huan Department of Anesthesiology Fuwai Cardiovascular Hospital Chinese Academy of Medical Sciences & Peking Union Medical College Beijing 100037 China

Background Studies suggested that anesthetics administered upon the early reperfusion or ＂anesthetic postconditioning＂ could protect post-ischemic hearts against myocardial ischemia reperfusion injury （MIRI）. However, the mechanism responsible for such protection was not well-elucidated. We investigated the cardioprotection induced by sevoflurane postconditioning （SpostC） in rat hearts in vitro, and the respective role of phosphatidylinositol-3-kinase （PI3K）, extracellular signal-regulated kinase 1 and 2 （ERK 1/2）, mitochondrial KATP channels （mitOKAme） and mitochondrial permeability transition pore （mPTP）, by selectively inhibiting PI3K, ERK 1/2, mitOKATP, with LY294002 （LY）, PD98059 （PD）, 5-hydroxydecanoate （5-HD） and by directly opening of mPTP with atractyloside （ATR）, respectively. Methods Isolated rat hearts were randomly assigned to one of the 12 groups （n=-15）： Time control （continuous perfusion）, ISCH （30 minutes of ischemia followed by 60 minutes of reperfusion alone）, SpostC （3% sevoflurane postconditioning was administered during the first 15 minutes of reperfusion after 30 minutes of ischemia）, ISCH＋LY, ISCH＋PD, ISCH＋ATR, ISCH＋5-HD and ISCH＋ dimethyl sulfoxide （DMSO） groups （LY, PD, ATR, 5-HD and DMSO （the vehicle） was administered respectively during the first 15 minutes of reperfusion following test ischemia）, SpostC＋LY, SpostC＋PD, SpostC＋ATR and SpostC＋5-HD groups （LY, PD, ATR and 5-HD was coadministered with 3% sevoflurane, respectively）. Hemodynamics was compared within and between groups. Infarction size was determined at the end of experiments using triphenyltetrazolium chloride （TTC） staining. Lactate dehydrogenase （LDH）, creatine kinase-MB （CK-MB） and cardiac troponin I （cTnl） released from necrotic myocardium, were compared among TC, ISCH and SpostC groups. To investigate the relationships between RISK and mPTP implicated in SpostC, NAD＋ content in myocardium, a marker of mPTP opening, was compared among some experimental groups （TC, ISCH, ISC

关键词： sevoflurane heart ischemia reperfusion

Quick moment tensor solution for 6 April 2009,L'Aquila,Italy,earthquake

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Earthquake Science 2009年第5期22卷 449-450页

作者： Chao Liu Lisheng Xu yun-tai Chen Institute of Geophysics China Earthquake Administration Beijing 100081 China School of Earth and Space Sciences Peking University Beijing 100871 China

A Mw6.4 earthquake occurred in L＇Aquila, central Italy at 1：32：42 （UTC）, April 6, 2009. We quickly obtained the moment tensor solution of the earthquake by inverting the P waveforms of broadband recordings from the global seismographic network （GSN） stations using the quick technique of moment tensor inversion, and further inferred that the nodal plane of strike 132°, dip 53° and rake -103° is the seismogenic fault.

关键词： L'Aquila earthquake moment tensor solution focal mechanism fault parameter