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一种用μ分析设计的舵减摇鲁棒控制器 被引量:6
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作者 杨承恩 贾欣乐 毕英君 《中国造船》 EI CSCD 北大核心 1999年第4期28-34,共7页
船舶模型不确定性严重影响着舵减摇的效果。本文用μ分析方法设计了一种H∞控制器来解决结构化模型不确定性的问题。用船舶线性模型和非线性模型模拟海上航行条件的计算仿真表明μ分析控制器具有良好的鲁棒特性。
关键词 横摇 舵减摇 鲁棒控制 从分析 船舶
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给孩子一个美名
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作者 佘茜 《现代教学》 2011年第1期124-124,共1页
[案例一:分心乎?空白乎?——一声叹息] 今天是班主任公开课展示的日子。上课前,我是满怀着信心的。我认为这堂课的内容很简单,主要是让学生了解“朋友”的涵义,体会到“有朋友”的快乐。在前几次的自理自省课上,班上学生发言踊... [案例一:分心乎?空白乎?——一声叹息] 今天是班主任公开课展示的日子。上课前,我是满怀着信心的。我认为这堂课的内容很简单,主要是让学生了解“朋友”的涵义,体会到“有朋友”的快乐。在前几次的自理自省课上,班上学生发言踊跃,分析问题头头是道。可是没想到,一开场就出洋相了,我让学生做“抛球”的游戏, 展开更多
关键词 从分析学生问题的产生原因入手
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Accurate ab initio Predictions of Ionization Energies and Heats of Formation for Cyclopropenylidene, Propargylene and Propadienylidene 被引量:1
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作者 K. C. Lau C. Y. Ng 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 北大核心 2006年第1期29-38,共10页
The ionization energies (IEs) of cyclopropenylidene (c-C3H2), propargylene (HCCCH) and propadienylidene (H2CCC) have been computed using the CCSD(T)/CBS method, which involves the approxixnation to the compl... The ionization energies (IEs) of cyclopropenylidene (c-C3H2), propargylene (HCCCH) and propadienylidene (H2CCC) have been computed using the CCSD(T)/CBS method, which involves the approxixnation to the complete basis set (CBS) limit at the coupled cluster level with single and double excitations plus quasi-perturbative triple excitation effect (CCSD(T)). The zero-point vibrational energy correction, the core-valence electronic correction, the scalar relativistic effect and the high level correction beyond the CCSD(T) excitations have also been made in these calculations. The CCSD(T)/CBS values for the IN(c-C3H2) and IE(HCCCH) of 9.164, 8.987 eV are in good agreement with the experimental values of (9.15±0.03) and (8.96±0.04) eV. The CCSD(T)/CBS calculations yield the IE values of 10.477 and 10.388 eV for the ionization transitions H2CCC→H2CCC^+ (^2A1, C2v) and H2CCC→H2CCC+ (^2A', Cs), respectively. On the basis of the Franek-Condon factor consideration, the IE of (10.43±0.02) eV determined in the previous single-photon ionization experiment most likely corresponds to the ionization threshold for the H2CCC→H2CCC^+(^2A1, C2v) transition. Although the precision of the experimental IN measurements fpr c-C3H2, HCCCH, and H2CCC is insufficient to pin down the accuracy of the theoretical calculations to better than ±30 meV, the excellent agreement between the experimental and theoretical IE values observed in the present study indicates that the CCSD(T)/CBS calculations together with high-order correlation corrections are capable of yielding reliable IE predictions for simple hydrocarbon carbenes and bi-radicals. We have also reported the heats of formation at 0 K (△H^of0) and 298 K (△H^of298)for c-C3H2/c-C3H2^+, HCCCH/HCCCH^+, and H2CCC/H2CCC^+, The available experimental △H^of0 and △H^of298 values for c-C3H2/c C3H2^+, HCCCH/HCCCH^+ are found to be in good accord with the CCSD(T)/CBS predictions after taking into account the experimental uncertainties. 展开更多
关键词 Ab intio Ionization energy Heat of formation c-C3H2 HCCCH H2CCC
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Molecular Dynamics Insights into Electron-Catalyzed Dissociation Repair of Cyclobutane Pyrimidine Dimer
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作者 Liang Gao Yuxiang Bu 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2021年第6期850-860,I0004,共12页
Excess electrons are not only an important source of radiation damage,but also participate in the repair process of radiation damage such as cyclobutane pyrimidine dimer(CPD).Using ab initio molecular dynamics(AIMD)si... Excess electrons are not only an important source of radiation damage,but also participate in the repair process of radiation damage such as cyclobutane pyrimidine dimer(CPD).Using ab initio molecular dynamics(AIMD)simulations,we reproduce the single excess electron stepwise catalytic CPD dissociation process in detail with an emphasis on the energy levels and molecular structure details associated with excess electrons.On the basis of the AIMD simulations on the CPD aqueous solution with two vertically added excess electrons,we exclude the early-proposed[2+2]-like concerted synchronous dissociation mechanism,and analyze the difference between the symmetry of the actual reaction and the symmetry of the frontier molecular orbitals which deeply impact the mechanism.Importantly,we propose a new model of the stepwise electron-catalyzed dissociation mechanism that conforms to the reality.This work not only provides dynamics insights into the excess electron catalyzed dissociation mechanism,but also reveals different roles of two excess electrons in two bond-cleavage steps(promoting versus inhibiting). 展开更多
关键词 Excess electron Cyclobutane pyrimidine dimer Electron catalysis Frontier orbital analysis Ab initio molecular dynamics simulation
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Grammar Consciousness-Raising Tasks and Intermediate Learners' Achievement and Perceptions
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作者 Seyyed Ali Ostovar Namaghi Maryam Charmchi 《Sino-US English Teaching》 2016年第1期1-7,共7页
While there is lots of empirical evidence showing that grammar consciousness raising tasks (GCRTs) have an edge over the traditional modes of grammar instruction, there is very little qualitative evidence reflecting... While there is lots of empirical evidence showing that grammar consciousness raising tasks (GCRTs) have an edge over the traditional modes of grammar instruction, there is very little qualitative evidence reflecting learners' perceptions of externally imposed educational changes including GCRTs. To extrapolate the previous findings and fill in this gap, this study aims to: (I) test the alleged superiority of GCRTs in grammar instruction and (2) explore learners' perceptions of learning grammar through GCRTs. To this end, this study used a mixed-method design including a quantitative and a qualitative dimension. The former dimension aimed at testing the superiority of GCRTs on a random sample of intermediate learners from Simin language school in Karaj, Iran through the robust Solomon-four-group design and the latter dimension aimed at collecting and analyzing qualitative interview data on learners' perceptions of GCRTs. The quantitative results clearly showed that learners being taught through GCRTs significantly outperformed those instructed through the traditional mode of grammar instruction and the qualitative analysis of learners' perspectives showed that the participants had a positive perception of GCRTs and this positive perception was rooted in GCRTs' potential to: (1) facilitate the internalization of grammar and (2) involve learners in discovery learning. The findings have clear implications for syllabus designers and practitioners. 展开更多
关键词 consciousness-raising tasks discovery learning willingness to learn traditional approach
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Exponential Synchronization of Master-Slave Lur'e Systems via Intermittent Time-Delay Feedback Control 被引量:1
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作者 王一晶 郝建娜 左志强 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第10期679-686,共8页
This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique... This paper concerns with the master-slave exponential synchronization analysis for a class of general Lur'esystems with time delay.Different from the previous methods based on the differential inequality technique, a newapproach is proposed to derive some new exponential synchronization criteria.The restriction that the control widthhas to be larger than the time delay is removed.This leads to a larger application scope for our method.Moreover, notranscendental equation is involved in the obtained result, which reduces the computational burden.Two examples aregiven to validate the theoretical results. 展开更多
关键词 exponential synchronization intermittent control delayed feedback control Razumikhin stabilitytheory Chua's circuits
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Adherence-A concept analysis in the context of cardiac rehabilitation
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作者 Hui Liu Xu Tian 《TMR Integrative Nursing》 2018年第1期12-17,共6页
Objective: To explore and identify the concept of adherence in the context of cardiac rehabilitation. This conceptanalysis will provide a framework for clinical decision-making and intervention to improve patients’ ... Objective: To explore and identify the concept of adherence in the context of cardiac rehabilitation. This conceptanalysis will provide a framework for clinical decision-making and intervention to improve patients’ adherence tocardiac rehabilitation programme. Method: Walker and Avant’s framework was used to analysis the concept ofadherence. Results: Adherence is defined as patients collaboration with health care provider, active involvement in thetreatment regimen, and persistence in practice characterized by self-efficacy and relapse-prevention. Defining Attributesof adherence include collaboration relationship; self-efficacy promotion and relapse-prevention. Antecedents ofadherence include health care provider’s prescription, illness perceptions, social-economic and environmental factors.Patients adherence to cardiac rehabilitation programme can improve clinical outcomes. However, there is no standardinstrument to measure adherence. Conclusion: Based on the concept analysis, in order to improve patients’ adherence tocardiac rehabilitation, health care provider should invite patients active involvement in making rehabilitation plan andpromote patients’ self-efficacy and prevention relapse. 展开更多
关键词 ADHERENCE COMPLIANCE PERSISTENCE Cardiac rehabilitation Concept analysis
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Next generation sequencing under de novo genome assembly 被引量:1
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作者 Sonia Farhana Nimmy M. S. Kamal 《International Journal of Biomathematics》 2015年第5期1-29,共29页
The next generation sequencing (NGS) is an important process which assures inexpen- sive organization of vast size of raw sequence dataset over any traditional sequencing systems or methods. Various aspects of NGS s... The next generation sequencing (NGS) is an important process which assures inexpen- sive organization of vast size of raw sequence dataset over any traditional sequencing systems or methods. Various aspects of NGS such as template preparation, sequencing imaging and genome alignment and assembly outline the genome sequencing and align- ment. Consequently, de Bruijn graph (dBG) is an important mathematical tool that graphically analyzes how the orientations are constructed in groups of nucleotides. Basi- cally, dBG describes the formation of the genome segments in circular iterative fashions. Some pivotal dBG-based de novo algorithms and software packages such as T-IDBA, Oases, IDBA-tran, Euler, Velvet, ABYSS, AllPaths, SOAPde novo and SOAPde novo2 are illustrated in this paper. Consequently, overlap layout consensus (OLC) graph-based algorithms also play vital role in NGS assembly. Some important OLC-based algorithms such as MIRA3, CABOG, Newbler, Edena, Mosaik and SHORTY are portrayed in this paper. It has been experimented that greedy graph-based algorithms and software pack- ages are also vital for proper genome dataset assembly. A few algorithms named SSAKE, SHARCGS and VCAKE help to perform proper genome sequencing. 展开更多
关键词 Next generation sequencing (NGS) short read sequence (SRS) de Bruijngraph (dBG) SOAP denovo2 overlap layout consensus.
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