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复数域加权最小二乘法在相量量测状态估计中的应用 被引量:7
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作者 程云峰 陆超 《电网技术》 EI CSCD 北大核心 2014年第3期700-706,共7页
基于相量量测的状态估计能提高状态估计的精度,而相量测量单元在高电压等级网络中的广泛配置为电力系统全相量量测状态估计提供了坚实的硬件基础,研究全相量量测状态估计意义重大。建立了基于全相量量测状态估计的量测方程,在此基础上... 基于相量量测的状态估计能提高状态估计的精度,而相量测量单元在高电压等级网络中的广泛配置为电力系统全相量量测状态估计提供了坚实的硬件基础,研究全相量量测状态估计意义重大。建立了基于全相量量测状态估计的量测方程,在此基础上建立了复数加权最小二乘法(complex field weighted least square,CWLS)状态估计模型。文中还对复数域下相量的误差特性和CWLS算法的抗差性进行了研究,同时详细分析了CWLS算法中权重的选取和不良数据的辨识。仿真结果表明了所建模型的合理性以及CWLS算法的有效性和适应性。 展开更多
关键词 相量测量单元 相量误差特性 线性状态估计 权重 改进标准化残差
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配电网小电流接地系统典型故障分析与处理 被引量:2
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作者 鹿优 徐伟 李毅然 《国网技术学院学报》 2018年第5期27-31,共5页
此文以配电网小电流接地系统典型故障分析与处理为主题,以目标电网的区域划分为切入点,总结了小电流接地系统单相接地故障的传统处理方式,以中性点不接地配电网永久性单相不完全接地故障为例,建立了电路模型,分析了故障特征和各电压的... 此文以配电网小电流接地系统典型故障分析与处理为主题,以目标电网的区域划分为切入点,总结了小电流接地系统单相接地故障的传统处理方式,以中性点不接地配电网永久性单相不完全接地故障为例,建立了电路模型,分析了故障特征和各电压的相量特性,提出了中性点不接地或经消弧线圈接地的配电网永久性单相不完全接地的故障相的判断方法;从运行方式的改变、配电自动化自动装置、故障选线选段和定位隔离的主流技术3个方面阐述了目前配电网小电流接地系统发生单相接地故障的处理过程。 展开更多
关键词 供电区域 小电流接地系统 单相接地故障 过渡电阻 相量特性
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Study of the Influence of Parent-brand Similarity,Association,and Complimentary Fit on Co-brand Attributes 被引量:1
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作者 沈蕾 《Journal of Donghua University(English Edition)》 EI CAS 2009年第5期565-571,共7页
In this paper,it investigates the factors affecting successive brand alliance in which two brands from different product categories are featured together to introduce a co-brand.Based on the brand alliance theories,th... In this paper,it investigates the factors affecting successive brand alliance in which two brands from different product categories are featured together to introduce a co-brand.Based on the brand alliance theories,the degree of association,similarity,and complimentary fit between parents brands are important factors in determining successive brand alliance.By using the 5P's,which are premium price,perceived quality,product features,performance,and perceived image,as the measuring scale in brand attributes for each brand,it has reflected the change of brand attributes of the brands before and after brand alliance.400 subjects participate in the research,and 360 of which are valid.From this study,we conclude that when association between parents turns from "-" to "+" and similarity from "-" to "0",there is a trend of descending of co-brand attributes.When fit between parents turns from "-" to "0",there is also a trend of descending of co-brand attributes.While fit between parents turns from "+" to "0",there is a trend of increasing of co-brand attributes.The results show an interesting pattern of interactions among factors,which has important implications for managers in co-brand marketing.These also provide researchers with promising avenues for further study in brand alliance. 展开更多
关键词 brand alliance brand association brandsimilarity brand complimentary fit
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Design of similarity measure for discrete data and application to multi-dimension 被引量:1
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作者 LEE Myeong-ho 魏荷 +2 位作者 LEE Sang-hyuk LEE Sang-min SHIN Seung-soo 《Journal of Central South University》 SCIE EI CAS 2013年第4期982-987,共6页
Similarity measure design for discrete data group was proposed. Similarity measure design for continuous membership function was also carried out. Proposed similarity measures were designed based on fuzzy number and d... Similarity measure design for discrete data group was proposed. Similarity measure design for continuous membership function was also carried out. Proposed similarity measures were designed based on fuzzy number and distance measure, and were proved. To calculate the degree of similarity of discrete data, relative degree between data and total distribution was obtained. Discrete data similarity measure was completed with combination of mentioned relative degrees. Power interconnected system with multi characteristics was considered to apply discrete similarity measure. Naturally, similarity measure was extended to multi-dimensional similarity measure case, and applied to bus clustering problem. 展开更多
关键词 similarity measure MULTI-DIMENSION discrete data relative degree power interconnected system
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Flow characteristics of three-phase foam in mine gob and its application
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作者 Shi Guoqing Liu Maoxi +1 位作者 Kong Jia Wang Deming 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第5期773-778,共6页
To study the flow characteristics of three-phase foam in gob area,different perfusion experiments in coal mine gob were designed and put forward in the paper.Through the observation of flow range,flow characteristics ... To study the flow characteristics of three-phase foam in gob area,different perfusion experiments in coal mine gob were designed and put forward in the paper.Through the observation of flow range,flow characteristics of three phase foam were analyzed with different flow rates.And,unsteady seepage process of three-phase foam was simulated with CFD software.Base on experiment and numerical simulation results,flow characteristics of three-phase foam and its major influence factors are discussed,and the optimal arrangement distribution of mine fire control drills is also determined.Research results show that the flow range and stacking height of three-phase foam in gob are significantly influenced by gravity.The vertical stacking height and horizontal diffusion distance of three-phase foam are also directly related to the flow volume of foam perfusion,the larger flow single hole perfusion volume,the higher stacking height and the longer diffusion distance could be obtained. 展开更多
关键词 Three-phase foam Gob area SEEPAGE Diffusion range Numerical simulation
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Property of Quantum Correlations with Correlated Noise
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作者 贺志 邹健 +1 位作者 李建 邵彬 《Communications in Theoretical Physics》 SCIE CAS CSCD 2010年第5期837-842,共6页
We analyze the classical and quantum correlation properties of the standard and so-called quasiclassical depolarizing channel with correlated noise and non-Markovian dephasing channel, specifically we use the quantum ... We analyze the classical and quantum correlation properties of the standard and so-called quasiclassical depolarizing channel with correlated noise and non-Markovian dephasing channel, specifically we use the quantum discord, entanglement, and measurement-induced disturbance (MID) to measure the quantum correlations. For the depolarizing channel, we find that the memory effect has more influence on the MID and quantum discord than entanglement. For the dephasing channel, we show that the non-Markovian dephasing channel is more robust than Markovian dephasing channel against deeoherence. We also find that at first MID and quantum discord take different values, and then after a specific time they will take almost the same value and both decay monotonically in the same way. 展开更多
关键词 ENTANGLEMENT quantum discord measurement-induced disturbance (MID) non-Markovian process
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Phase Properties of Nonlinear Coherent States
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作者 SONGTong-Qing ZHUYue-Jin 《Communications in Theoretical Physics》 SCIE CAS CSCD 2002年第5期606-610,共5页
Using the Pegg-Barnett formalism we study the phase probability distributions and the squeezing effects of measured phase operators in the nonlinear coherent states introduced by R.L. de Matos Filho and W. Vogel to de... Using the Pegg-Barnett formalism we study the phase probability distributions and the squeezing effects of measured phase operators in the nonlinear coherent states introduced by R.L. de Matos Filho and W. Vogel to describe the center-of mass motion of a trapped ion and the q-coherent states. Moreover, we have obtained the completeness relation of nonlinear coherent states and proved that the q-Fock state \n>(q) introduced in many papers is, in fact, the usual Fock state. 展开更多
关键词 nonlinear coherent state phase probability distribution measured phase operators
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Testing for Nonlinearity in Dynamic Characteristics of Vertical Upward Oil-Gas-Water Three-phase Bubble and Slug Flows 被引量:1
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作者 朱雷 金宁德 +2 位作者 高忠科 杜萌 王振亚 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2012年第5期870-882,共13页
Based on the conductance fluctuation signals measured from vertical upward oil-gas-water three-phase flow experiment, time frequency representation and surrogate data method were used to investigate dynamical characte... Based on the conductance fluctuation signals measured from vertical upward oil-gas-water three-phase flow experiment, time frequency representation and surrogate data method were used to investigate dynamical characteristics of oil-in-water type bubble and slug flows. The results indicate that oil-in-water type bubble flow will turn to deterministic motion with the increase of oil phase fraction f o and superficial gas velocity U sg under fixed flowrate of oil-water mixture Q mix . The dynamics of oil-in-water type slug flow becomes more complex with the increase of U sg under fixed flowrate of oil-water mixture. The change of f o leads to irregular influence on the dynamics of slug flow. These interesting findings suggest that the surrogate data method can be a faithful tool for characterizing dynamic characteristics of oil-in-water type bubble and slug flows. 展开更多
关键词 oil-gas-water three-phase flow conductaJace fluctuating signals time-frequency representation surrogate data method
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Using acoustic technique to detect leakage in city gas pipelines 被引量:2
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作者 陈志刚 连香姣 赫亮 《Journal of Central South University》 SCIE EI CAS 2012年第8期2373-2379,共7页
For solving the difficult problem of leakage detection in city gas pipelines, a method using acoustic technique based on instantaneous energy (IE) distribution and correlation analysis was proposed. Firstly, the basic... For solving the difficult problem of leakage detection in city gas pipelines, a method using acoustic technique based on instantaneous energy (IE) distribution and correlation analysis was proposed. Firstly, the basic theory of leakage detection and location was introduced. Then the physical relationship between instantaneous energy and structural state variation of a system was analyzed theoretically. With HILBERT-HUANG transformation (HHT), the instantaneous energy distribution feature of an unstable acoustic signal was obtained. According to the relative contribution method of the instantaneous energy, the noise in signal was eliminated effectively. Furthermore, in order to judge the leakage, the typical characteristic of the instantaneous energy of signal in the input and output end was discussed using correlative analysis. A number of experiments were carried out to classify the leakage from normal operations, and the results show that the leakages are successfully detected and the average recognition rate reaches 93.3% among three group samples. It is shown that the method using acoustic technique with IED and correlative analysis is effective and it may be referred in other pipelines. 展开更多
关键词 city gas pipeline leakage detection acoustic technique instantaneous energy distribution correlative analysis
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Action Recognition from a Different View 被引量:1
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作者 陈昌红 干宗良 《China Communications》 SCIE CSCD 2013年第12期139-148,共10页
In this paper,we propose a novel approach to recognise human activities from a different view.Although appearance-based recognition methods have been shown to be unsuitable for action recognition for varying views,the... In this paper,we propose a novel approach to recognise human activities from a different view.Although appearance-based recognition methods have been shown to be unsuitable for action recognition for varying views,there must be some regularity among the same action sequences of different views.Selfsimilarity matrices appear to be relative stable across views.However,the ability to effectively realise this stability is a problem.In this paper,we extract the shape-flow descriptor as the low-level feature and then choose the same number of key frames from the action sequences.Self-similarity matrices are obtained by computing the similarity between any pair of the key frames.The diagonal features of the similarity matrices are extracted as the highlevel feature representation of the action sequence and Support Vector Machines(SVM) is employed for classification.We test our approach on the IXMAS multi-view data set.The proposed approach is simple but effective when compared with other algorithms. 展开更多
关键词 action recognition different view shape-flow descriptor self-similarity matrix diagonal feature
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Reliability and validity of Chinese version of a tool to assess the quality of life in idiopathic pulmonary fibrosis in patients with interstitial lung disease 被引量:1
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作者 Rui-Li Pan Jeffrey J.Swigris +3 位作者 Yan-Wei Zhao Ai-Min Guo Qing Wu Si-Jia Li 《International Journal of Nursing Sciences》 CSCD 2019年第1期38-42,共5页
Objective:This paper aims to determine the reliability and validity of the Chinese version of a tool that assesses the quality of life in idiopathic pulmonary fibrosis(cATAQ-IPF)in patients with interstitial lung dise... Objective:This paper aims to determine the reliability and validity of the Chinese version of a tool that assesses the quality of life in idiopathic pulmonary fibrosis(cATAQ-IPF)in patients with interstitial lung disease(ILD).Methods:We used the process of scale introduction to establish cATAQ-IPF.The content validity of the scale was evaluated by six experts.A total of 92 patients with ILD completed the cATAQ-IPF,St.George's respiratory questionnaire(SGRQ),and The Medical Research Council dyspnoea scale at the baseline,and 15 patients completed cATAQ-IPF at the follow-up period 2 weeks later.Thus,yielding data were used to assess various psychometric properties of cATAQ-IPE Intraclass correlation coefficient(ICC),Cronbach'sαcoefficient,content validity index(CVI),item-level CVI(I-CVI),Pearson's coefficients,criterion-relation validity,and known-group validity were used for data analysis.Results:The cATAQ-IPF showed excellent test-retest reliability(ICC=0.95),except for the therapy domain(Cronbach'sα=0.60)and acceptable internal consistency(Cronbach'sα=0.96 for the total).The scale-level CVI was 0.80,and the I-CVI was in the range of 0.78-1.00.The total cATAQ-IPF score was strongly correlated with the SGRQ total score(r=0.71,P<0.01).The cATAQ-IPF score of patients with ILD was 250.74±47.39,and that of patients with IPF was 287.90±22.56.Patients with IPF possessed considerable impairments in health-related quality of life according to the cATAQ-IPF score(t=4.94,P<0.01).Conclusions:The cATAQ-IPF is a reliable and valid instrument for the evaluation of quality of life of Chinese patients with various forms of ILD. 展开更多
关键词 Health related quality of life Interstitial lung disease ATAQ-IPF RELIABILITY Validity
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On the Interpretation of the Foundations of Quantum Mechanics
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作者 Valery Egorushkin 《Journal of Physical Science and Application》 2012年第8期315-327,共13页
This study discusses the information space, the wave function phase, the Berry phase and its relationship to quantization, discriminability of states and macroscopic quantum effects caused by localization of the parti... This study discusses the information space, the wave function phase, the Berry phase and its relationship to quantization, discriminability of states and macroscopic quantum effects caused by localization of the particle, followed by a possible entropy change during its transition into a new thermodynamic state. This work addresses interference: it is the information waves which interfere; the particles follow their roadmap, and the measurement of their coordinates introduces an additional uncertainty into the momentum. It is not particles (matter) which manifest these wave properties but fluctuations of the physical space-time coordinates. Physical characteristics corresponding to the fluctuating variables, energy, momentum, etc., determine the magnitude of the respective fluctuations rather than the wave properties of matter. Matter possesses no wave properties. This work also discusses the difference between the objective information and knowledge. 展开更多
关键词 Quantum theory FLUCTUATIONS WAVEFUNCTION quantum interference corpuscular-wave dualism.
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The Influence of Particle Interactions on the Existence of Quantum Particles Properties
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作者 Tomer Shushi 《Journal of Physical Science and Application》 2015年第3期196-198,共3页
We propose a novel model, based on two postulates, which provide new perspective on the fundamental forces using special and general relativity concepts. Many studies address the relations between the particles and th... We propose a novel model, based on two postulates, which provide new perspective on the fundamental forces using special and general relativity concepts. Many studies address the relations between the particles and the space time manifold, and the latter's physical structure, whether it is Continuous or Discrete. In the proposed model the properties of the particles are classical in the sense of general relativity, whereas their quantum properties are arises due to the experiments. 展开更多
关键词 Interference pattern particle's structure quantum theory.
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Nonlinear Quantum Optical Springs and Their Nonclassical Properties
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作者 M.J.Faghihi M.K.Tavassoly 《Communications in Theoretical Physics》 SCIE CAS CSCD 2011年第8期327-332,共6页
The original idea of quantum optical spring arises from the requirement of quantization of the frequency of oscillations in the Hamiltonian of harmonic oscillator. This purpose is achieved by considering a spring whos... The original idea of quantum optical spring arises from the requirement of quantization of the frequency of oscillations in the Hamiltonian of harmonic oscillator. This purpose is achieved by considering a spring whose constant (and so its frequency) depends on the quantum states ofanother system. Recently, it is realized that by the assumption of frequency modulation of ω to ω √1+ μα+α the mentioned idea can be established. In the present paper, we generalize the approach of quantum optical spring with particular attention to the dependence or trequency to the intensity of radiation field that naturally observes in the nonlinear coherent states, from which we arrive at a physical system has been called by us as nonlinear quantum optical spring. Then, after the introduction of the generalized tlamiltonian of nonlinear quantum optical spring and it's solution, we will investigate the nonclassical properties of the obtained states. Specially, typical collapse and revival in the distribution functions and squeezing parameters, as particular quantum features, will be revealed. 展开更多
关键词 nonlinear coherent states quantum optical spring nonclassical states
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A feature selection approach based on a similarity measure for software defect prediction 被引量:3
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作者 Qiao YU Shu-juan JIANG +1 位作者 Rong-cun WANG Hong-yang WANG 《Frontiers of Information Technology & Electronic Engineering》 SCIE EI CSCD 2017年第11期1744-1753,共10页
Software defect prediction is aimed to find potential defects based on historical data and software features. Software features can reflect the characteristics of software modules. However, some of these features may ... Software defect prediction is aimed to find potential defects based on historical data and software features. Software features can reflect the characteristics of software modules. However, some of these features may be more relevant to the class (defective or non-defective), but others may be redundant or irrelevant. To fully measure the correlation between different features and the class, we present a feature selection approach based on a similarity measure (SM) for software defect prediction. First, the feature weights are updated according to the similarity of samples in different classes. Second, a feature ranking list is generated by sorting the feature weights in descending order, and all feature subsets are selected from the feature ranking list in sequence. Finally, all feature subsets are evaluated on a k-nearest neighbor (KNN) model and measured by an area under curve (AUC) metric for classification performance. The experiments are conducted on 11 National Aeronautics and Space Administration (NASA) datasets, and the results show that our approach performs better than or is comparable to the compared feature selection approaches in terms of classification performance. 展开更多
关键词 Software defect prediction Feature selection Similarity measure Feature weights Feature ranking list
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Functional nanogenerators as vibration sensors enhanced by piezotronic effects 被引量:6
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作者 Zheng Zhangt Qingliang Liao +6 位作者 Xiaoqin Yan Zhong Lin Wang Wenduo Wang Xu Sun Pei Lin Yunhua Huang Yue Zhang 《Nano Research》 SCIE EI CAS CSCD 2014年第2期190-198,共9页
ZnO nanomaterials have been shown to have novel applications in optoelectronics, energy harvesting and piezotronics, due to their coupled semiconducting and piezoelectric properties. Here a functional nanogenerator (... ZnO nanomaterials have been shown to have novel applications in optoelectronics, energy harvesting and piezotronics, due to their coupled semiconducting and piezoelectric properties. Here a functional nanogenerator (FNG) based on ZnO nanowire arrays has been fabricated, which can be employed to detect vibration in both self-powered (SP) and external-powered (EP) modes. In SP mode, the vibration responses of the FNG can be measured through converting mechanical energy directly into an electrical signal. The FNG shows consistent alternating current responses (relative error 〈 0.37%) at regular frequencies from 1 to 15 Hz. In EP mode, the current responses of FNG are significantly enhanced via the piezotronic effect. Under a forward bias of 3 V, the sensor presented a sensitivity of 3700% and an accurate measurement (relative error 〈 0.91%) of vibration frequencies in the range 0.05-15 Hz. The results show that this type of functional nanogenerator sensor can detect vibration in both SP and EP modes according to the demands of the applications. 展开更多
关键词 functional nanogenerator ZnO nanowires arrays piezotronic effects piezoelectric effects vibration sensor
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Measurement-Based Interference in Quantum Computation
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作者 徐酉阳 《Communications in Theoretical Physics》 SCIE CAS CSCD 2013年第9期289-295,共7页
The interference has been measured by the visibility in two-level systems, which, however, does not work for multi-level systems. We generalize a measure of the interference based on decoherence process, consistent wi... The interference has been measured by the visibility in two-level systems, which, however, does not work for multi-level systems. We generalize a measure of the interference based on decoherence process, consistent with the visibility in qubit systems. By taking duster states as examples, we show in the one-way quantum computation that the gate fidelity is proportional to the interference of the measured qubit and is inversely proportional to the interference of all register qubits. We also find that the interference increases with the number of the computing steps. So we conjecture that the interference may be the source of the speedup of the one-way quantum computation. 展开更多
关键词 quantum interference quantum computation quantum speedup
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Analysis on spectral gain characteristics of PPMgLN based quasi-phase-matching optical parametric amplification 被引量:1
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作者 Hai-bin XU Bo WU +1 位作者 Shuang-shuang CAI Yong-hang SHEN 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2009年第4期601-606,共6页
A deep understanding of the spectral gain characteristics of optical parametric oscillators (OPOs) and optical parametric amplifiers (OPAs) is important for a highly efficient optical parametric conversion. We numeric... A deep understanding of the spectral gain characteristics of optical parametric oscillators (OPOs) and optical parametric amplifiers (OPAs) is important for a highly efficient optical parametric conversion. We numerically calculated the spectral gain characteristics of a quasi-phase-matching (QPM) parametric conversion process using the periodically poled 6% (mol/mol) MgO doped LiNbO3 (PPMgLN) as the nonlinear crystal. In the simulation we utilized the approach of a transformative matrix of the periodically poled nonlinear medium, which results from the small-signal approximation of three-wave mixed nonlinear equations. Numerical simulation results show that: (1) The full width at half maximum (FWHM) of the spectral gain of the parametric process becomes wider with the increase of parametric wavelength and reaches the maximum at degeneration; (2) The gain coefficient decreases gradually with the increase of parametric wavelength; (3) The spectral gain bandwidth decreases correspondingly with the increase of the nonlinear material length; (4) There exists an optimal parametric wavelength band, which is most suitable for the high gain parametric conversion when pumped by a laser source with a wide wavelength band, such as the high power fiber laser. 展开更多
关键词 Spectral gain full width at half maximum (FWHM) Quasi-phase matching (QPM) Optical parametric conversion PPMGLN
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Influence of ring-down cavity parameters on intensity transmission property in trace gas concentration measurement
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作者 李志全 闫聚兵 +1 位作者 孙宇超 李文超 《Optoelectronics Letters》 EI 2011年第6期470-474,共5页
In this paper, we describe the basic principles and system design of continuous wave cavity ring-down spectroscopy (CWCRDS). We also particularly study the nature and the behavior of a novel method to detune a laser... In this paper, we describe the basic principles and system design of continuous wave cavity ring-down spectroscopy (CWCRDS). We also particularly study the nature and the behavior of a novel method to detune a laser and apply it to a cavity ring-down spectroscopy experiment. Both simulations and experiments are completed on the relation between the transmission characteristic and different refiectivities, as well as scanning speed. Output electric field equation is deduced. It has been investigated that how photons are coupled to the cavity and how to accumulate the intensity and leak out of the cavity as a function of time. It is noted that both accumulation of intensity and decay times decrease, and the oscillation amplitude increases as the reflectivity increases. Relative intensity increases with decreasing scanning velocity. Additionally, the simulations show that a non-detuned cavity displays the transmitted signals which are highly dependent on the mirror reflectivity and piezoelectric translator (PZT) modulation speed. Simulations also display that the laser switching off is different from dettming. 展开更多
关键词 Electric fields EXPERIMENTS Systems analysis
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