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东亚经济格局的变动及其对两岸经贸关系的影响 被引量:1
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作者 张远鹏 《亚太经济》 CSSCI 北大核心 2007年第2期21-25,共5页
20世纪90年代以来,东亚经济格局发生重大变化,由日本″单极″变成了中日″双头″。这一变化导致两岸经济从单方面的依赖到互相依赖;在贸易平衡、外汇储备等方面台湾对祖国大陆更加依赖;台商投资从短期经营到本土化经营;两岸产业分工从... 20世纪90年代以来,东亚经济格局发生重大变化,由日本″单极″变成了中日″双头″。这一变化导致两岸经济从单方面的依赖到互相依赖;在贸易平衡、外汇储备等方面台湾对祖国大陆更加依赖;台商投资从短期经营到本土化经营;两岸产业分工从产业间发展到产业内、产品内;两岸从企业间一般技术合作到行业组织间标准方面的合作。 展开更多
关键词 东亚经济格局 “单极” “双头” 两岸经贸
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Diode Pumped Monolithic Unidirectional Nonplanar Single-Frequency Ring Laser 被引量:1
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作者 吴克瑛 赵长明 +5 位作者 史俊峰 魏光辉 刘安汉 崔连荣 朱震 洪冬梅 《Journal of Beijing Institute of Technology》 EI CAS 2001年第2期175-179,共5页
Diode pumped monolithic nonplanar ring laser has been developed, yielding single frequency laser and has the advantages of compactness, reliability and high efficiency. Its principles are given in detail and a monolit... Diode pumped monolithic nonplanar ring laser has been developed, yielding single frequency laser and has the advantages of compactness, reliability and high efficiency. Its principles are given in detail and a monolithic nonplanar ring laser is designed. As a result, a laser of hundreds milliwatts cw single frequency output was built up, placed in a magnetic field and pumped by LD. The optical conversion efficiency was more than 15% and the slope efficiency more than 30%. The laser beam had a good quality, with M 2 about 1 2. 展开更多
关键词 SINGLE-FREQUENCY diode pumped solid state laser
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Temperature Dependence of Performance of 6H-SiC Unipolar Power Devices
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作者 何进 张兴 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2001年第10期1235-1239,共5页
The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytica... The temperature dependence of some performance of 6H SiC unipolar power devices is analyzed theoretically.By employing the temperature dependent ionization coefficient and mobility of a silicon carbide,the analytical expressions of the temperature dependent performance,such as breakdown characteristics and on resistance of 6H SiC unipolar power devices are derived in a closed form.The analytical results are compared with the experimental results,with good accordance found in the breakdown characteristics. 展开更多
关键词 wide band gap semiconductor devices 6H SiC impact ionization coefficient avalanche breakdown on resistance temperature dependence of performance
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Novel band-notched UWB antenna for WUSB system
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作者 何小祥 邓宏伟 《Journal of Southeast University(English Edition)》 EI CAS 2008年第4期424-427,共4页
A simple and compact microstrip-fed ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed for wireless universal serial-bus (WUSB). The antenna is composed of a U-shaped line radi... A simple and compact microstrip-fed ultra wideband (UWB) printed monopole antenna with band-notched performance is proposed for wireless universal serial-bus (WUSB). The antenna is composed of a U-shaped line radiator and a small strip bar and is partially grounded, so that the measured impedance bandwidth of the antenna is about 7. 88 GHz covering 3. 12 to 11 GHz with VSWR below 2, and the expected band rejection of 5.06 to 5. 89 GHz is also obtained. The characteristics of the proposed antenna are analyzed, and the geometric parameters for optimal performance are investigated in detail. A relatively stable, quasi-omnidirectional and quasi-symmetrical radiation pattern is also found. The proposed band-notched UWB antenna requires no external filters to avoid interference with other systems, and thus, greatly simplifies the system design of an ultra wideband WUSB communication system. 展开更多
关键词 wireless universal serial-bus (WUSB) printed antenna monopole antenna ultra wideband (UWB) BAND-NOTCHED
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Fabrication and Field Emission of Silicon Nano-Crystalline Film 被引量:1
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作者 王伟明 郁可 +2 位作者 丁艳芳 李琼 朱自强 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2004年第6期639-644,共6页
The silicon nano-crystalline (nc-Si) film is fabricated on <100> orientation,0.01Ω·cm resistivity,and p-type boron-doped silicon wafer by the anodic etching.The microstructure and the orientation of nc-Si ... The silicon nano-crystalline (nc-Si) film is fabricated on <100> orientation,0.01Ω·cm resistivity,and p-type boron-doped silicon wafer by the anodic etching.The microstructure and the orientation of nc-Si are examined by the scanning electron microscopy,transmission electron microscopy,and X-ray diffraction spectroscopy,respectively.The average size of particle is estimated by Raman spectroscopy.The results show that the particle size of nc-Si film is scattered from 10nm to 20nm,the alignment is compact,the orientation is uniform,the expansion of lattice constant is negligible,and mechanical robustness and stability are good.The correlations between film structure and the experiment parameters such as etching time,HF concentration,and etching current density are discussed.As a potential application,efficient field emission is observed from the nc-Si film,and the turn-on field is about 3V/μm at 0.1μA/cm 2 of current density,which is close to carbon nanotube film's. 展开更多
关键词 NC-SI anodic etching uniform orientation field emission
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力量对比的变与不变——伊拉克战争与世界格局的变化及调整
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作者 朱锋 《国际贸易》 CSSCI 北大核心 2003年第6期32-35,共4页
伊拉克战争无疑是当代国际关系中的一个历史性事件.伊拉克战争究竟对国际战略格局及世界政治产生了什么样的影响,目前普遍存在着争论.
关键词 伊拉克战争 世界格局 世界政治 国际关系 力量对比 “单极体系” 大国合作
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Effects of Rotational Isomerism and Bond Length Alternation on Optical Spectra of FTC Chromophore in Solution
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作者 赵珂 韩广超 +1 位作者 张立立 贾海洪 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第1期75-81,I0004,共8页
Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)-thien-5]-E-vinylg-5,5-... Rotational isomerism effects on the optical spectra of a push-pull nonlinear optical chro-mophore 2-dicyanomethylen-3-cyano-4-f2-[E-(4-N,N-di(2-acetoxyethyl)-amino)-phenylene-(3,4-dibutyl)-thien-5]-E-vinylg-5,5-dimethyl-2,5-dihydrofuran (FTC) in a few solvents have been studied using the time-dependent density functional theory in combination with the polarizable continuum model. It is shown that the maximum absorption peaks of the ro-tamers have difference of nearly 30 nm both in vacuum and in solutions. The population of the rotamers changes a lot in different solvents. Based on the geometries optimized by Hartree-Fock method, the Maxwell-Boltzmann averaged absorption has been calculated and the maximum absorption peak is in good agreement with experiment. It indicates that the bond length alternation can have an important effect on the optical spectra. 展开更多
关键词 Rotational isomerism Bond length alternation One-photon absorption Po-larizable continuum model
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A C-Band Monolithic GaAs PIN Diode SPST Switch
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作者 吴茹菲 张健 +1 位作者 尹军舰 张海英 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2008年第5期879-882,共4页
A monolithic single pole single throw (SPST) switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an... A monolithic single pole single throw (SPST) switch is developed with GaAs PIN diode technology from IMECAS. A novel small signal model of a GaAs PIN diode is developed for circuit simulation. The switch features an on-state insertion loss of less than 1.6dB and a return loss of greater than 10dB while maintaining an off-state isolation of greater than 23dB from 5.5 to 7. 5GHz. The measured 1dB power gain compression point is about 20dBm. 展开更多
关键词 C-BAND SPST switches OaAs PIN diodes
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H桥级联SVG的载波移相调制技术研究 被引量:9
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作者 常志琴 孙丽玲 谢欢 《电测与仪表》 北大核心 2014年第4期66-72,共7页
级联多电平高压大容量变流器已广泛应用于电力系统中,载波移相式正弦脉宽调制(CPS-SPWM)技术非常适用于大功率变流器场合。文中分别介绍了双极性CPS-SPWM调制方法和单极倍频CPS-SPWM调制方法,并基于PSCAD/EMTDC软件搭建仿真模型,采用频... 级联多电平高压大容量变流器已广泛应用于电力系统中,载波移相式正弦脉宽调制(CPS-SPWM)技术非常适用于大功率变流器场合。文中分别介绍了双极性CPS-SPWM调制方法和单极倍频CPS-SPWM调制方法,并基于PSCAD/EMTDC软件搭建仿真模型,采用频谱分析方法对其进行对比,结果表明采用双极性CPS-SPWM调制方法输出电压的最低次谐波群出现在N(N是指每相级联单元数)倍的载波频率附近,其等效开关频率提高了N倍,采用单极倍频CPS-SPWM调制方法的输出电压的最低次谐波群出现在2N倍的载波频率附近,其等效开关频率提高了2N倍,因此采用单极倍频CPS-SPWM调制方法其输出波形更接近正弦波,具有更好的消除谐波的特性。 展开更多
关键词 大功率变流器 开关频率 仿真模型
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Finite element failure analysis of continuous prestressed concrete box girders 被引量:4
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作者 张峰 李术才 +2 位作者 李树忱 叶见曙 雷笑 《Journal of Southeast University(English Edition)》 EI CAS 2009年第2期236-240,共5页
In order to analyze the load carrying capacity of prestressed concrete box girders, failure behaviors of in-situ deteriorated continuous prestressed concrete box girders under loading are experimentally observed and a... In order to analyze the load carrying capacity of prestressed concrete box girders, failure behaviors of in-situ deteriorated continuous prestressed concrete box girders under loading are experimentally observed and a finite failure analysis method for predicting behaviors of box girders is developed. A degenerated solid shell element is used to simulate box girders and material nonlinearity is considered. Since pre-stressed concrete box girders usually have a large number of curve prestressed tendons, a type of combined element is presented to simulate the prestressed tendons of box girders, and then the number of elements can be significantly reduced. The analytical results are compared with full-scale failure test results. The comparison shows that the presented method can be effectively applied to the failure analysis of in-situ continuous prestressed concrete box girders, and it also shows that the studied old bridge still has enough load carrying capacity. 展开更多
关键词 full-scale failure test prestressed concrete box girder finite element analysis combined element prestressed tendon load carrying capacity
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A New Method to Investigate InGaAsP Single-Photon Avalanche Diodes Using a Digital Sampling Oscilloscope
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作者 刘伟 杨富华 吴孟 《Journal of Semiconductors》 EI CAS CSCD 北大核心 2006年第10期1711-1716,共6页
A near-infrared single-photon detection system is established by using pigtailed InGaAs/InP avalanche photodiodes. With a 50GHz digital sampling oscilloscope, the function and process of gated-mode (Geiger-mode) sin... A near-infrared single-photon detection system is established by using pigtailed InGaAs/InP avalanche photodiodes. With a 50GHz digital sampling oscilloscope, the function and process of gated-mode (Geiger-mode) single-photon detection are intuitionally demonstrated for the first time. The performance of the detector as a gated-mode single-photon counter at wavelengths of 1310 and 1550nm is investigated. At the operation temperature of 203K,a quantum efficiency of 52% with a dark count probability per gate of 2.4 × 10 ^-3 ,and a gate pulse repetition rate of 50kHz are obtained at 1550nm. The corresponding parameters are 43%, 8.5 × 10^-3 , and 200kHz at 238K. 展开更多
关键词 InGaAsP single-photon avalanche diode 50GHz digital sampling oscilloscope gated-mode
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Anti-periodic solutions to a class of second-order evolution equations
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作者 张莉娜 薛星美 《Journal of Southeast University(English Edition)》 EI CAS 2003年第4期432-436,共5页
In this paper we discuss the anti-periodic problem for a class of abstractnonlinear second-order evolution equations associated with maximal monotone operators in Hilbertspaces and give some new assumptions on operato... In this paper we discuss the anti-periodic problem for a class of abstractnonlinear second-order evolution equations associated with maximal monotone operators in Hilbertspaces and give some new assumptions on operators. We establish the existence and uniqueness ofanti-periodic solutions, which improve andgeneralize the results that have been obtained. Finally weillustrate the abstract theory by discussing a simple example of an anti-periodic problem fornonlinear partial differential equations. 展开更多
关键词 maximal monotone operator anti-periodic solution poincare inequality second-order evolution equations
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Design and construction of a film of mesoporous single-crystal rutile TiO_2 rod arrays for photoelectrochemical water oxidation 被引量:2
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作者 甄超 吴亭亭 +3 位作者 Mohammad W.Kadi Iqbal Ismail 刘岗 成会明 《Chinese Journal of Catalysis》 SCIE EI CAS CSCD 北大核心 2015年第12期2171-2177,共7页
A film of mesoporous single-crystal rutile TiO2 rod arrays supported on a transparent conductive glass substrate was synthesized with the assistance of a template layer of closely packed silica nanospheres. This film ... A film of mesoporous single-crystal rutile TiO2 rod arrays supported on a transparent conductive glass substrate was synthesized with the assistance of a template layer of closely packed silica nanospheres. This film was used as a photoanode and showed significant improvement for photoelectrochemical water oxidation compared with a reference film of nonporous single-crystal rutile TiO2rod arrays. 展开更多
关键词 TITANIA PHOTOANODE MESOPORE Single crystal Rod array
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Compact ultra-wideband monopole antenna with dual-band notched function
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作者 石红艳 腾飞 +1 位作者 刘璐璐 高飞 《Journal of Measurement Science and Instrumentation》 CAS 2014年第1期56-60,共5页
A kind of compact ultra wideband (UWB) monopole antenna with dual-band notched function is presented.The proposed antenna,using "C" and "L" apertures embedded in the annular ring patch and ground patch,gets two ... A kind of compact ultra wideband (UWB) monopole antenna with dual-band notched function is presented.The proposed antenna,using "C" and "L" apertures embedded in the annular ring patch and ground patch,gets two bandnotched characteristics in WiMAX3.5 GHz and WLAN 5.5 GHz.The size of antenna is 24 mm × 36 mm × 1.6 mm.The simulation results show that waveband range of the antenna is 2.7-10.6 GHz for S11 <-10 dB and the band-notched wavebands are 3.2-3.8 GHz and 5.1-6 GHz.So it has miniaturization,ultra-band and band-notched characteristics.Meanwhile,the radition pattern,directivety and gain are perfect,which meets the practical need. 展开更多
关键词 dual-band notched ultra wideband monopole antenna
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Quantum Entropy of Black Hole with Internal Global Monopole 被引量:4
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作者 HANYi-Wen YANGShu-Zheng LIUWen-Biao 《Communications in Theoretical Physics》 SCIE CAS CSCD 2005年第2期382-384,共3页
Using the generalized uncertainty relation, the new equation of state density is obtained, and then the entropy of black hole with an internal global monopole is discussed. The divergence that appears in black hole en... Using the generalized uncertainty relation, the new equation of state density is obtained, and then the entropy of black hole with an internal global monopole is discussed. The divergence that appears in black hole entropy calculation through original brick-wall model is overcome. The result of the direct proportion between black hole entropy and its event horizon area is drawn and given. The result shows that the black hole entropy must be the entropy of quantum state near the event horizon. 展开更多
关键词 generalized uncertainty relation state density quantum entropy black hole
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Intestinal disease of scattered mirror carp Cyprinus carpio caused by Thelohanellus kitauei and notes on the morphology and phylogeny of the myxosporean from Sichuan Province,southwest China 被引量:4
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作者 叶灵通 卢明淼 +5 位作者 权可艳 李文祥 邹红 吴山功 王江勇 王桂堂 《Chinese Journal of Oceanology and Limnology》 SCIE CAS CSCD 2017年第3期587-596,共10页
The mass mortality of pond-reared scattered mirror carp, Cyprinus carpio, caused by Thelohanellus kitauei, occurred at fish farms in Sichuan Province, southwest China. Morphological and molecular analyses were supplem... The mass mortality of pond-reared scattered mirror carp, Cyprinus carpio, caused by Thelohanellus kitauei, occurred at fish farms in Sichuan Province, southwest China. Morphological and molecular analyses were supplemented with histological evaluation of infected tissues to better understand the route of infection and the pathological effects of 1". kitauei on the fish host. The intestine of the diseased host was full of large cysts of the myxosporean. The cysts range from 2 cm to 3.6 cm in diameter. Histopathology indicated that T. kitauei first invaded the submucosa of the host intestine and then moved into the mucosa layers with the development of their spores, finally entering into the enteric cavity of the hosts after the disruption of mucosa layers. The pyriform spores of T. kitauei were surrounded by the transparent spore sheath, measuring 25.98/μm±0.95 μm in body length, 8.72 μm±0.51μm body width, and 7.86 μm±0.26 μm in body thickness. The single polar capsule was pyriform, measuring 14.73 μm±0.92μm in length and 6.82 μm±0.45μm in width, with eight to 10 turns of filament coils winding inside. Phylogenetic analysis based on the 18S small-subunit ribosomal DNA sequences indicated that minimal genetic differences were present between T. kitauei samples from South Korea and from China. Close affinity was found between the genus Thelohanellus and Myxobolus. Additionally, two polar capsule nuclei were found at the anterior end of the single polar capsule in spores of T. kitauei stained with hematoxylin and eosin, which suggested the separation of the genus Thelohanellus from Myxobolus. 展开更多
关键词 intestinal disease scattered mirror carp Thelohanellus kitauei host-specific tropism MORPHOLOGY PHYLOGENY
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Quantum Tunneling Radiation of Reissner-Nordstrom de Sitter Black Hole with a Global Monopole 被引量:2
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作者 JIANG Qing-Quan YANG Shu-Zheng LI Hui-Ling 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3期457-460,共4页
Applying Parikh's quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon an... Applying Parikh's quantum tunneling model, we study the quantum tunneling radiation of Reissne- Nordstrom de Sitter black hole with a global monopole. The result shows that the tunneling rates at the event horizon and the cosmic horizon are related to Bekenstein-Hawking entropy if we take the energy conservation into consideration, and the true radiate spectrum is not precisely thermal. 展开更多
关键词 Reissner-Nordstrom de Sitter black hole global monopole energy conservation tunneling rate
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Correction to Hawking Tunneling Radiation from Global Monopole Charged BlackHole 被引量:2
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作者 LI Hui-Ling YANG Shu-Zheng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2009年第1期190-192,共3页
Considering the self-gravitation and energy conservation as well as charge conservation, we extend Medved and Vagenas's quantum tunneling method to the global monopole charged black hole, and give a correction to Haw... Considering the self-gravitation and energy conservation as well as charge conservation, we extend Medved and Vagenas's quantum tunneling method to the global monopole charged black hole, and give a correction to Hawking radiation of a charged particle. 展开更多
关键词 Hawking tunneling radiation energy conservation charge conservation SELF-GRAVITATION
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Y(sl(2)) Algebra Application in Extended Hydrogen Atom and Monopole Models 被引量:1
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作者 TIANLi-Jun ZHANGHong-Biao +1 位作者 JINShuo XUEKang 《Communications in Theoretical Physics》 SCIE CAS CSCD 2004年第5期641-644,共4页
We present the extended hydrogen atom and monopole-hydrogen atom theory through generalizing the usual hydrogen atom model and with a monopole model respectively, in which Y (sl(2) ) algebras are realized. We derive t... We present the extended hydrogen atom and monopole-hydrogen atom theory through generalizing the usual hydrogen atom model and with a monopole model respectively, in which Y (sl(2) ) algebras are realized. We derive the Hamiltonians of the two models based on the Y(sl(2) ) and the generalized Pauli equation. The energy spectra of the systems are also given in terms of Yangian algebra and quantum mechanics. 展开更多
关键词 YANGIAN Y(sl(2)) loop algebra extended hydrogen MONOPOLE
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Comparison of the Outcomes of Monopolar and Bipolar Radiofrequency Ablation in Surgical Treatment of Atrial Fibrillation 被引量:1
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作者 Wei-zhao Huang Ying-meng Wu +1 位作者 Hong-yu Ye Hai-ming Jiang 《Chinese Medical Sciences Journal》 CAS CSCD 2014年第1期28-32,共5页
Objective To compare the therapeutic effects and safety of monopolar and bipolar radiofrequency(RF) ablation used during cardiac surgery to treat atrial fibrillation.Methods We retrospectively studied a total of 81 pa... Objective To compare the therapeutic effects and safety of monopolar and bipolar radiofrequency(RF) ablation used during cardiac surgery to treat atrial fibrillation.Methods We retrospectively studied a total of 81 patients with chronic atrial fibrillation who underwent open cardiac surgery with concomitant RF ablation between January 2007 and March 2011.Fifty-eight patients received bipolar RF ablation and 23 received monopolar RF ablation,respectively.The sinus rhythm restoration rate,the procedural duration,the frequency of severe perioperative complications,and mortality were compared between the two groups.Results The sinus rhythm restoration rate did not differ significantly between the two groups after follow-up of 15.1 ± 12.6 months(P=0.199).The frequencies of severe perioperative complications and mortality were also similar in the two groups.The total procedural time using bipolar RF ablation was significantly shorter than that using monopolar ablation(19.7±4.6 minutes vs.28.1±8.5 minutes,P< 0.001).Conclusions Both monopolar and bipolar RF ablation are safe and effective in treating chronic atrial fibrillation patients during open cardiac surgery,but bipolar RF ablation is more convenient in practice. 展开更多
关键词 atrial fbrillafion radiofrequency ablation cardiac surgery Maze procedure
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