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Third-line rescue therapy for Helicobacter pylori infection 被引量:31
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作者 Rossella Cianci Massimo Montalto +2 位作者 Franco Pandolfi Giovan Battista Gasbarrini Giovanni Cammarota 《World Journal of Gastroenterology》 SCIE CAS CSCD 2006年第15期2313-2319,共7页
H pylori gastric infection is one of the most prevalent infectious diseases worldwide. The discovery that most upper gastrointestinal diseases are related to Hpylori infection and therefore can be treated with antibio... H pylori gastric infection is one of the most prevalent infectious diseases worldwide. The discovery that most upper gastrointestinal diseases are related to Hpylori infection and therefore can be treated with antibiotics is an important medical advance. Currently, a first-line triple therapy based on proton pump inhibitor (PPI) or ranitidine bismuth citrate (RBC) plus two antibiotics (darithromycin and amoxicillin or nitroimidazole) is recommended by all consensus conferences and guidelines. Even with the correct use of this drug combination, infection can not be eradicated in up to 23% of patients. Therefore, several second line therapies have been recommended. A 7 d quadruple therapy based on PPI, bismuth, tetracycline and metronidazole is the more frequently accepted. However, with second-line therapy, bacterial eradication may fail in up to 40% of cases. When Hpylori eradication is striclly indicated the choice of further treatment is controversial. Currently, a standard third-line therapy is lacking and various protocols have been proposed. Even after two consecutive failures, the most recent literature data have demonsbated that Hpylori eradication can be achieved in almost all patients, even when antibiotic susceptibility is not tested. Different possibilities of empirical treatment exist and the available third-line strategies are herein reviewed. 展开更多
关键词 Helicobacter pylori third-line rescue therapy Antimicrobial resistance LEVOFLOXACIN RIFABUTIN FURAZOLIDONE DOXYCYCLINE
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Third-line and rescue therapy for refractory Helicobacter pylori infection: A systematic review 被引量:4
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作者 Pedro Vieira de Moraes Andrade Yan Mosca Monteiro Ethel Zimberg Chehter 《World Journal of Gastroenterology》 SCIE CAS 2023年第2期390-409,共20页
BACKGROUND Due to increasing resistance rates of Helicobacter pylori(H.pylori)to different antibiotics,failures in eradication therapies are becoming more frequent.Even though eradication criteria and treatment algori... BACKGROUND Due to increasing resistance rates of Helicobacter pylori(H.pylori)to different antibiotics,failures in eradication therapies are becoming more frequent.Even though eradication criteria and treatment algorithms for first-line and second-line therapy against H.pylori infection are well-established,there is no clear recommendation for third-line and rescue therapy in refractory H.pylori infection.AIM To perform a systematic review evaluating the efficacy and safety of rescue therapies against refractory H.pylori infection.METHODS A systematic search of available rescue treatments for refractory H.pylori infection was conducted on the National Library of Medicine’s PubMed search platform based on Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines.Randomized or non-randomized clinical trials and observational studies evaluating the effectiveness of H.pylori infection rescue therapies were included.RESULTS Twenty-eight studies were included in the analysis of mean eradication rates as rescue therapy,and 21 of these were selected for analysis of mean eradication rate as third-line treatment.For rifabutin-,sitafloxacin-,levofloxacin-,or metronidazole-based triple-therapy as third-line treatment,mean eradication rates of 81.6%and 84.4%,79.4%and 81.5%,55.7%and 60.6%,and 62.0%and 63.0%were found in intention-to-treat(ITT)and per-protocol(PP)analysis,respectively.For third-line quadruple therapy,mean eradication rates of 69.2%and 72.1%were found for bismuth quadruple therapy(BQT),88.9%and 90.9%for bismuth quadruple therapy,three-in-one,Pylera®(BQT-Pylera),and 61.3%and 64.2%for non-BQT)in ITT and PP analysis,respectively.For rifabutin-,sitafloxacin-,levofloxacin-,or metronidazole-based triple therapy as rescue therapy,mean eradication rates of 75.4%and 78.8%,79.4 and 81.5%,55.7%and 60.6%,and 62.0%and 63.0%were found in ITT and PP analysis,respectively.For quadruple therapy as rescue treatment,mean eradication rates of 76.7%and 79.2%for BQT,84.9%and 87.8%for BQT-Pylera,and 61.3%and 64.2%for non-BQT were found in ITT and PP analysis,respectively.For susceptibility-guided therapy,mean eradication rates as third-line and rescue treatment were 75.0%in ITT and 79.2%in PP analysis.CONCLUSION We recommend sitafloxacin-based triple therapy containing vonoprazan in regions with low macrolide resistance profile.In regions with known resistance to macrolides or unavailability of bismuth,rifabutin-based triple therapy is recommended. 展开更多
关键词 Helicobacter pylori Refractory infection third-line therapy Rescue therapy ERADICATION Treatment
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Efficacy analysis and multi-factor retrospective study of third-line chemotherapy in 82 Chinese patients with small cell lung cancer
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作者 Jingjing Liu Shuang Zhang +4 位作者 Lixia Ma Chunjiao Wu Changliang Yang Xuerong Zuo Ying Cheng 《The Chinese-German Journal of Clinical Oncology》 CAS 2015年第1期26-31,共6页
Objective As there is currently no clear recommendation for third-line chemotherapy for small cell lung cancer (SCLC), its efficacy is unknown. To date, there have rarely been reports of Chinese patients with SCLC w... Objective As there is currently no clear recommendation for third-line chemotherapy for small cell lung cancer (SCLC), its efficacy is unknown. To date, there have rarely been reports of Chinese patients with SCLC who received third-line chemotherapy. Therefore, we investigated the efficacy, safety, and prognostic factors of Chinese patients with SCLC treated with third-line chemotherapy. Methods A retrospective analysis of patients with SCLC who received third-line chemotherapy was performed. Results Between 2007 and 2013, 62 patients [62 men (75.6%), 20 women (24.4%); median age at the time of diagnosis, 55 years] received third-line chemotherapy at our center. Of these patients, 44 had limited-stage disease and 38 had extensive-stage disease. On third-line chemotherapy, 55 (67.1%) patients had an Eastern Cooperative Oncology Group performance status (ECOG PS) of 0-1, objective response rate of 15.9%, and median overall survival after third-line chemotherapy (OS-3) and median progres- sion-free survival after third-line chemotherapy (PFS-3) of 5.6 months and 3.0 months, respectively. On univariate analysis, PFS-3 was significantly related with ECOG PS (P = 0.005), response to second-line chemotherapy (P = 0.002), response to third-line chemotherapy (P 〈 0.001), and PFS after second-line chemotherapy (P = 0.026). OS-3 was significantly related with ECOG PS (P 〈 0.001), response to third-line chemotherapy (P = 0.033), PFS after first-line therapy (P = 0.044), and PFS after second-line therapy (PFS-2) (P = 0.007). On multivariate analysis, ECOG PS (P = 0.008) and response to third-line chemotherapy (P = 0.046) were independent prognostic factors for PFS-3, while ECOG PS (P = 0.007) and PFS-2 (P 〈 0.001) were independent prognostic factors for OS-3. Conclusion Few patients with SCLC receive third-line chemotherapy. Our findings suggest that patients with an ECOG PS 0-1 and PFS-2 for 〉3 months will be benefit from third-line chemotherapy, which should be actively offered to them. 展开更多
关键词 small cell lung cancer third-line chemotherapy prognostic factors
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THE LIMIT CYCLE BIFURCATIONS OF A WHIRLING PENDULUM WITH PIECEWISE SMOOTH PERTURBATIONS
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作者 杨纪华 《Acta Mathematica Scientia》 SCIE CSCD 2024年第3期1115-1144,共30页
This paper deals with the problem of limit cycles for the whirling pendulum equation x=y,y=sin x(cosx-r)under piecewise smooth perturbations of polynomials of cos x,sin x and y of degree n with the switching line x=0.... This paper deals with the problem of limit cycles for the whirling pendulum equation x=y,y=sin x(cosx-r)under piecewise smooth perturbations of polynomials of cos x,sin x and y of degree n with the switching line x=0.The upper bounds of the number of limit cycles in both the oscillatory and the rotary regions are obtained using the Picard-Fuchs equations,which the generating functions of the associated first order Melnikov functions satisfy.Furthermore,the exact bound of a special case is given using the Chebyshev system.At the end,some numerical simulations are given to illustrate the existence of limit cycles. 展开更多
关键词 whirling pendulum limit cycle Melnikov function Picard-Fuchs equation Chebyshev system
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Reduced-Order Observer-Based LQR Controller Design for Rotary Inverted Pendulum
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作者 Guogang Gao LeiXu +2 位作者 Tianpeng Huang Xuliang Zhao Lihua Huang 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期305-323,共19页
The Rotary Inverted Pendulum(RIP)is a widely used underactuated mechanical system in various applications such as bipedal robots and skyscraper stabilization where attitude control presents a significant challenge.Des... The Rotary Inverted Pendulum(RIP)is a widely used underactuated mechanical system in various applications such as bipedal robots and skyscraper stabilization where attitude control presents a significant challenge.Despite the implementation of various control strategies to maintain equilibrium,optimally tuning control gains to effectively mitigate uncertain nonlinearities in system dynamics remains elusive.Existing methods frequently rely on extensive experimental data or the designer’s expertise,presenting a notable drawback.This paper proposes a novel tracking control approach for RIP,utilizing a Linear Quadratic Regulator(LQR)in combination with a reduced-order observer.Initially,the RIP system is mathematically modeled using the Newton-Euler-Lagrange method.Subsequently,a composite controller is devised that integrates an LQR for generating nominal control signals and a reduced-order observer for reconstructing unmeasured states.This approach enhances the controller’s robustness by eliminating differential terms from the observer,thereby attenuating unknown disturbances.Thorough numerical simulations and experimental evaluations demonstrate the system’s capability to maintain balance below50Hz and achieve precise tracking below1.4 rad,validating the effectiveness of the proposed control scheme. 展开更多
关键词 Rotary inverted pendulum(RIP) linear quadratic regulator(LQR) reduced-order observer states estimate
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Astral Actions on Allais’ Pendulum Apparently Inexplicable by Classical Factors: A Point of the Situation
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作者 Jean-Bernard Deloly 《Journal of Modern Physics》 2024年第9期1375-1408,共34页
1) The observation by Allais of the precession of pendulums from 1954 to 1960 highlighted regularities of astral origin an in-depth analysis of which showed that, apparently, no classical phenomenon can explain them. ... 1) The observation by Allais of the precession of pendulums from 1954 to 1960 highlighted regularities of astral origin an in-depth analysis of which showed that, apparently, no classical phenomenon can explain them. These regularities were diurnal waves whose periods are characteristic of astral influence (the main ones being 24 h and 24 h 50 min), annual and semi-annual components, and a multi-annual component of approximately 6 years, an influence of Jupiter being a very good candidate to explain it. 2) Allais had experimentally established that all these astral influences were expressed globally on the pendulum by an action tending to call back its plane of oscillation towards a direction variable in time, and which ovalized its trajectory. In 2019 the observation of 2 pendulums in Horodnic (Romania), thanks to the use of an automatic alidade, made it possible to identify the main mechanism that, very probably, acted on the pendulum to achieve this result. This perturbation model, called “linear anisotropy”, is characterized by its “coefficient of anisotropy” η, and by the azimuth of its “direction of anisotropy”. The composition of 2 linear anisotropies is always a linear anisotropy. 3) In the search for the phenomena which could be at the origin of all what precedes, the fact that they must create an ovalization immediately eliminates some of them. 4) We have calculated the values of η corresponding to the 24 h and 24 h 50 min waves both for the observations in Horodnic and the Allais observations. The order of magnitude (some 10−7) is effectively the same in both cases. 5) Mathematically, the regularities discovered may result of a new force field but also, as Allais proposes, from the creation, under the astral influences, of a local anisotropy of the medium in which the pendulum oscillates. In the first case the length of the pendulum is involved, in the second one not. The data available do not make it possible to decide. 6) The joint exploitation, in mechanics and optics, of Allais observations and of observations by other experimenters provides additional information: a) Allais, and after him several other scientists, discovered also marked anomalies in the precession of pendulums during certain eclipses, and maybe certain other syzygies. For the few eclipses for which both something was observed and sufficient data were available (one of them being a lunar eclipse for which nothing had been published until now), it was always the above perturbation model which acted on the pendulum, but sometimes with quite exceptional magnitude. b) There are quite possible links with optics. During the observation campaign of August 1958, which had implemented both two pendulums and an optical device, all the 24 h 50 min waves were almost in phase. In the precession of the Allais pendulum, in Miller’s interferometric observations in Mont Wilson, and in Esclangon’s observations in Strasbourg, a same peculiarity is found: the extrema of the annual influence are at the equinoxes, not at the solstices. 展开更多
关键词 Allais Effect pendulum Lunisolar Influence Jupiter Influence Lunar and Solar Eclipses SYZYGIES SUNSPOTS Solar Cycles
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Pendulum矫治器远中移动磨牙治疗Ⅱ类错的临床及头影测量评价 被引量:7
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作者 贺红 韩光丽 +2 位作者 张漫 华先明 陈方俊 《口腔医学纵横》 CSCD 2001年第4期243-246,共4页
目的 :探讨Pendulum矫治器治疗Ⅱ类错牙合的临床疗效及对牙颌面的影响。方法 :应用Pendulum矫治器对18例平均年龄为 11.9岁的牙性Ⅱ类错牙合患者进行治疗 ,通过治疗前后的头影测量分析 ,评价其对牙颌面的影响。结果 :Pendulum矫治器能... 目的 :探讨Pendulum矫治器治疗Ⅱ类错牙合的临床疗效及对牙颌面的影响。方法 :应用Pendulum矫治器对18例平均年龄为 11.9岁的牙性Ⅱ类错牙合患者进行治疗 ,通过治疗前后的头影测量分析 ,评价其对牙颌面的影响。结果 :Pendulum矫治器能够远中移动上颌磨牙致磨牙关系为Ⅰ类或偏近中 ,未见开牙合及明显前牙支抗丧失。结论 展开更多
关键词 pendulum矫治器 Ⅱ类错He 治疗 磨牙远中移动 头影测量 正畸治疗
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改良Pendulum与改良Jones远移磨牙的对比分析 被引量:1
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作者 张琳林 吴杨 +3 位作者 邹林洪 张定铭 李欣 戴红卫 《重庆医科大学学报》 CAS CSCD 北大核心 2011年第4期483-486,共4页
目的:探讨改良Pendulum矫治器、改良Jones装置推磨牙向远中的疗效。方法:选择22例轻中度前牙拥挤的安氏Ⅱ类错病例,介于拔牙和不拔牙矫治的边缘,所有病例被平均随机分配在2个组,分别采用2种装置推磨牙向远中,在治疗前后进行X线头影测... 目的:探讨改良Pendulum矫治器、改良Jones装置推磨牙向远中的疗效。方法:选择22例轻中度前牙拥挤的安氏Ⅱ类错病例,介于拔牙和不拔牙矫治的边缘,所有病例被平均随机分配在2个组,分别采用2种装置推磨牙向远中,在治疗前后进行X线头影测量和模型测量分析,采用SPSS软件对数据进行分析。结果:2组远中移动效果均比较明显,但在移动速度、磨牙中央窝宽度差、前牙覆差、上颌第二前磨牙以及第一磨牙的倾斜度的统计分析上差异有统计学意义。结论:改良Pendulum矫治器J、ones装置均可有效地推上颌磨牙向远中移动,但改良Jones组磨牙向远中更少发生倾斜移动,矫治时间短,移动速度更快,对前牙支抗消耗相对较低。 展开更多
关键词 改良pendulum矫治器 改良Jones装置 磨牙远中移动 安氏Ⅱ类错
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EQUATION OF MOTION FOR NOVEL FRICTION PENDULUM SYSTEM WITH DUAL ROLLERS 被引量:9
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作者 袁健 ROSCHKE Paul 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI 2005年第4期276-280,共5页
A novel friction pendulum system (FPS) with dual rollers is studied based on the multibody dynamics theory. By analyzing kinematic characteristics of the system, it is reduced to a one degree-of-freedom system. Then... A novel friction pendulum system (FPS) with dual rollers is studied based on the multibody dynamics theory. By analyzing kinematic characteristics of the system, it is reduced to a one degree-of-freedom system. Then the equation of motion for the system is analytically derived by applying the theorem of the relative kinetic energy for a system of particles in differential form in the non-inertial reference system described as a nonlinear differential equation. In the case of the small angular displacement, the natural frequency of the corresponding undamped linear system is obtained, which is consistent with the experimental observation. The derived equation is useful for the study of dynamic characteristics of novel FPS, and its solution directly expedites the simulation of the system in a control loop, and further facilitates the semi-active control process including novel FPS. 展开更多
关键词 friction pendulum system with dual rollers seismic isolation analytical study multibody system
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Pendulum矫治器远中移动磨牙治疗Ⅱ类错的临床应用
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作者 林铭 《广东医学》 CAS CSCD 北大核心 2005年第11期1527-1527,共1页
关键词 pendulum矫治器 磨牙移动术 Ⅱ类错[牙合] 临床应用 适应证
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Pendulum矫治器在上颌牙列前段拥挤中的临床应用
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作者 程平 《中国实用医药》 2008年第10期115-116,共2页
目的评价Pendulum矫治器在解除上颌牙列前段拥挤中的临床效果。方法选择安氏Ⅱ类(前牙区拥挤3-5mm)患者11例,其中女7例,男4例,年龄10.6-12.9岁,平均11.5岁,采用Pendulum矫治器推磨牙向远中来解除牙列前段的拥挤,疗程为2-3个月。结果... 目的评价Pendulum矫治器在解除上颌牙列前段拥挤中的临床效果。方法选择安氏Ⅱ类(前牙区拥挤3-5mm)患者11例,其中女7例,男4例,年龄10.6-12.9岁,平均11.5岁,采用Pendulum矫治器推磨牙向远中来解除牙列前段的拥挤,疗程为2-3个月。结果每侧磨牙向后移动2.5-5mm,患者矫治前后侧面型无明显改变,但上颌第二磨牙术前偏颊向位的其间距增加1.5-2.0mm。结论Pendulum矫治器能有效地移动上颌磨牙,快速解除上颌牙前段的轻中度拥挤。但可能导致原来偏颊向位的第二磨牙在矫治后更趋颊向位,临床治疗中须引起注意。 展开更多
关键词 pendulum矫治器 错[牙合] 临床应用 牙列
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四阶受迫摆方程周期解的存在性
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作者 于文源 韩晓玲 《四川师范大学学报(自然科学版)》 CAS 2025年第1期132-137,共6页
运用Mawhin延拓定理研究四阶受迫摆方程x(4)+a(t)sin x=e(t)周期解的存在性,其中a(t)和e(t)是连续的T-周期函数.同时,作为结论的应用,也给出一些具体的例子来说明所得结论的适用性.
关键词 周期解 受迫摆方程 四阶微分方程 Mawhin延拓定理
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Pendulum联合推簧矫治安氏Ⅱ类错伴尖牙阻生
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作者 曲虹 于渤 《现代口腔医学杂志》 CAS CSCD 2010年第5期393-395,共3页
关键词 非拔牙矫治 安氏Ⅱ类错[牙合] pendulum 尖牙阻生 家族遗传病史 青春发育高峰期 口腔不良习惯 系统性疾病
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Design of A Hydraulic Power Take-off System for the Wave Energy Device with An Inverse Pendulum 被引量:13
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作者 张大海 李伟 +2 位作者 赵海涛 鲍经纬 林勇刚 《China Ocean Engineering》 SCIE EI CSCD 2014年第2期283-292,共10页
This paper describes a dual-stroke acting hydraulic power take-off (PTO) system employed in the wave energy converter (WEC) with an inverse pendulum. The hydraulic PTO converts slow irregular reciprocating wave mo... This paper describes a dual-stroke acting hydraulic power take-off (PTO) system employed in the wave energy converter (WEC) with an inverse pendulum. The hydraulic PTO converts slow irregular reciprocating wave motions to relatively smooth, fast rotation of an electrical generator. The design of the hydraulic PTO system and its control are critical to maximize the generated power. A time domain simulation study and the laboratory experiment of the full-scale beach test are presented. The results of the simulation and laboratory experiments including their comparison at full-scale are also presented, which have validated the rationality of the design and the reliability of some key components of the prototype of the WEC with an inverse pendulum with the dual-stroke acting hydraulic PTO system. 展开更多
关键词 SIMULATION dual-stoke acting power take-off (PTO) laboratory experiment inverse pendulum wave energy converter
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前方牵引和Pendulum在临床上的联合应用 被引量:6
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作者 阎振梅 《大连医科大学学报》 CAS 2004年第2期115-118,共4页
[目的 ]对适合做前方牵引矫正的患者在牵引后存在牙列不齐的问题进行研究。 [方法 ]对替牙期Ⅲ类错牙合的患者共计 2 8例 (男性 1 6例 ,女性 1 2例 ) ,用前方牵引的方法进行矫正。在解除反牙合后 ,6 6 ┼6 6 为远中关系的患者 8例 ,使用... [目的 ]对适合做前方牵引矫正的患者在牵引后存在牙列不齐的问题进行研究。 [方法 ]对替牙期Ⅲ类错牙合的患者共计 2 8例 (男性 1 6例 ,女性 1 2例 ) ,用前方牵引的方法进行矫正。在解除反牙合后 ,6 6 ┼6 6 为远中关系的患者 8例 ,使用Pendulum调整6 6 ┼6 6 的咬牙合关系。余下的患者6 6 ┼6 6 为远中关系的患者 1 0例对照观察。 [结果 ]用前方牵引矫正反牙合 ,X光头影测量分析可见A点明显前移SNA明显增大 ,ANB改善明显。不做Pendulum的 1 0例患者6 6 ┼6 6 的位置关系和拥挤度无明显变化。做Pendulum的患者可维持6 6 ┼6 6 中性关系 ,拥挤度明显减少。 [结论 ]前方牵引后或多或少出现6 ┼6 的前移 ,造成牙性Ⅱ类错牙合。Pendulum是以上颌前部齿槽骨和前牙为支抗 ,后移磨牙来矫正牙源性Ⅱ类错牙合。这样牙齿的拥挤量减少或消失 ,在使用固定矫正器进行治疗时减少了减数拔牙的可能性 ,在排齐牙列时降低前牙的唇倾度。 展开更多
关键词 pendulum 前方牵引 Ⅲ类错He 拥挤度
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Optimal feedback gains of a delayed proportional-derivative(PD) control for balancing an inverted pendulum 被引量:5
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作者 Qiang Wang Zaihua Wang 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2017年第3期635-645,共11页
In the dynamics analysis and synthesis of a controlled system, it is important to know for what feedback gains can the controlled system decay to the demanded steady state as fast as possible. This article presents a ... In the dynamics analysis and synthesis of a controlled system, it is important to know for what feedback gains can the controlled system decay to the demanded steady state as fast as possible. This article presents a systematic method for finding the optimal feedback gains by taking the stability of an inverted pendulum system with a delayed proportional-derivative controller as an example. First, the condition for the existence and uniqueness of the stable region in the gain plane is obtained by using the D-subdivision method and the method of stability switch. Then the same procedure is used repeatedly to shrink the stable region by decreasing the real part of the rightmost characteristic root. Finally, the optimal feedback gains within the stable region that minimizes the real part of the rightmost root are expressed by an explicit formula. With the optimal feedback gains, the controlled inverted pendulum decays to its trivial equilibrium at the fastest speed when the initial values around the origin are fixed. The main results are checked by numerical simulation. 展开更多
关键词 Inverted pendulum Time delay Stability Rightmost characteristic root Optimal feedback gain
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Equivalent series system to model a multiple friction pendulum system with numerous sliding interfaces for seismic analyses 被引量:7
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作者 C.S.Tsai H.C.Su T.C.Chiang 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2014年第1期85-99,共15页
Current structural analysis software programs offer few if any applicable device-specifi c hysteresis rules or nonlinear elements to simulate the precise mechanical behavior of a multiple friction pendulum system(MFPS... Current structural analysis software programs offer few if any applicable device-specifi c hysteresis rules or nonlinear elements to simulate the precise mechanical behavior of a multiple friction pendulum system(MFPS) with numerous sliding interfaces.Based on the concept of subsystems,an equivalent series system that adopts existing nonlinear elements with parameters systematically calculated and mathematically proven through rigorous derivations is proposed.The aim is to simulate the characteristics of sliding motions for an MFPS isolation system with numerous concave sliding interfaces without prior knowledge of detailed information on the mobilized forces at various sliding stages.An MFPS with numerous concave sliding interfaces and one articulated or rigid slider located between these interfaces is divided into two subsystems: the fi rst represents the concave sliding interfaces above the slider,and the second represents those below the slider.The equivalent series system for the entire system is then obtained by connecting those for each subsystem in series.The equivalent series system is validated by comparing numerical results for an MFPS with four sliding interfaces obtained from the proposed method with those from a previous study by Fenz and Constantinou.Furthermore,these numerical results demonstrate that an MFPS isolator with numerous concave sliding interfaces,which may have any number of sliding interfaces,is a good isolation device to protect structures from earthquake damage through appropriate designs with controllable mechanisms. 展开更多
关键词 seismic isolation base isolation earthquake engineering multiple friction pendulum system structural control mathematical modeling equivalent series system
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HUMAN-IMITATING INTELLIGENT CONTROL AND TRIPLE INVERTED-PENDULUM 被引量:4
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作者 Zhang Minglian Hao Jiankang He Weidong (305, Department of Automatic Control, Beijing University of Aeronautics and Astronautics, Beijing, China, 100083)Sun Changling(Department of Automation, Tsinghua University, Beijing, China, 100084) 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 1996年第2期135-146,共12页
A 'Human-Imitating Intelligent Control Theory' with 'generalized reduction' and 'Human Imitating' concepts as its kernel is proposed. And a world puzzlein the control circles is solved successf... A 'Human-Imitating Intelligent Control Theory' with 'generalized reduction' and 'Human Imitating' concepts as its kernel is proposed. And a world puzzlein the control circles is solved successfully based on this theory. The puzzle is thewell-known 'triple inverted pendulum control' using a SINGLE motor. A human-imitating intelligent technique to control inverted pendulum is here described. The success. ful experimental results show that our control objective can be achieved without a precise mathematical model of the plant. Finally, general principles of designing complexautomatic control systems based on the human-imitating intelligent control theory areconcluded. 展开更多
关键词 artificial intelligence pendulumS automatic control control systems design
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Dynamic performance of cable-stayed bridge tower with multi-stage pendulum mass damper under wind excitations——I:Theory 被引量:4
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作者 郭安薪 徐幼麟 李惠 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2007年第3期295-306,共12页
In this paper, wind-induced vibration control of a single column tower of a cable-stayed bridge with a multi- stage pendulum mass damper (MSPMD) is investigated. Special attention is given to overcoming space limita... In this paper, wind-induced vibration control of a single column tower of a cable-stayed bridge with a multi- stage pendulum mass damper (MSPMD) is investigated. Special attention is given to overcoming space limitations for installing the control device in the tower and the effect of varying natural frequency of the towers during construction. First, the finite element model of the bridge during its construction and the basic equation of motion of the MSPMD are introduced. The equation of motion of the bridge with the MSPMD under along-wind excitation is then established. Finally, a numerical simulation and parametric study are conducted to assess the effectiveness of the control system for reducing the wind-induced vibration of the bridge towers during construction. The numerical simulation results show that the MSPMD is practical and effective for reducing the along-wind response of the single column tower, can be installed in a small area of the tower, and complies with the time-variant characteristics of the bridge during its entire construction stage. 展开更多
关键词 multi-stage pendulum mass damper cable-stayed bridge single column tower wind-induced vibration
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Pendulum systems for harvesting vibration energy from railroad tracks and sleepers during the passage of a high-speed train: A feasibility evaluation 被引量:2
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作者 Franco E.Dotti Mauricio D.Sosa 《Theoretical & Applied Mechanics Letters》 CAS CSCD 2019年第4期229-235,I0005,共8页
We evaluate the feasibility of recovering energy from the vibrations of track and sleepers,during passage of a high-speed train,by means of a pendulum harvester.A simple mathematical model of the parametric pendulum i... We evaluate the feasibility of recovering energy from the vibrations of track and sleepers,during passage of a high-speed train,by means of a pendulum harvester.A simple mathematical model of the parametric pendulum is employed to obtain numerical predictions,while measured data of vibration tests during the passage of a Thalys high-speed train are considered as input forcing.Since a sustained rotation is the most energetic motion of a pendulum,the possibility of achieving such state is evaluated,taking into account the influence of initial conditions,damping and other factors.Numerical simulations show that rotating pendulum harvesters with sufficiently low viscous damping could be able to generate a usable average power on the order of 5–6 W per unit.Considering a modular arrangement of devices,such energy is enough to feed variety of rail-side equipment,as wireless sensors or warning light systems.However,a suitable choice of initial conditions could be a difficult task,leading to the need of a control action. 展开更多
关键词 Energy HARVESTING Parametric pendulum RAILROAD safety TRAIN induced vibration
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