线性光电耦合器关键传递性能参数测试方法研究

线性光耦与普通光耦内部结构不同,因此普通光耦的测试方法不适用于对线性光耦的参数测试。针对线性光耦的传递性能参数缺乏统一的测试方法的问题,文中选取带宽、传递系数、非线性度三个关键参数进行测试方法研究。其中带宽使用脉冲测试方法,传递系数使用电流测试方法,非线性度使用公式法计算。选取HCNR200线性光耦为研究对象,仿真HCNR200线性光电耦合器的带宽测试,试验测试HCNR200线性光耦实物的带宽、传递系数及非线性度,进行误差分析。试验结果表明,测试方法能够有效反应器件的传递性能,具有较高的准确性。

Quantitative similarity assessment of non-linear chemical fingerprint of traditional Chinese medicine by similarity system theory

The similarities of the non-linear chemical （NLC） fingerprints of Radix Glycyrrhizaes from four producing areas and eight other traditional Chinese medicines （TCMs） were calculated, using a systemic similarity calculation method proposed and three other main calculation ones （Euclidean distance, correlation coefficient and included angle cosine）. All of the correlation coefficient similarities of different TCMs are higher than 0.952, and the included angle cosines are all higher than 0.962. So, both the conelation coefficient and included angle cosine similarities are unable to be used as the criteria for quantitatively evaluating the similarities of NLC fingerprints of TCMs. Although all of the Euclidean distance similarities of Berry Liquorices from four producing areas are less than 73, those of the other eight TCMs are all more than 180. The Euclidean distance cannot reflect the relative magnitudes of the feature differences in the NLC fingerprints very correctly. The systemic similarity method is the best among the four ones. All of the systemic similarities of Berry Liquorices from the four producing areas are higher than 0.962, while those of the other eight TCMs are all lower than 0.805, and the systemic similarity can reflect the differences between samples most faithfully, and can be used as a quantitative one evaluating the similarities of NLC fingerprints of TCMs, by which TCM could be distinguished and evaluated quickly, simply and exactly.

A Nonlinear Restoring Effect Study of Mooring System and its Application

Mooring system plays an important role in station keeping of floating offshore structures. Coupled analysis on mooring-buoy interactions has been increasingly studied in recent years. At present, chains and wire ropes are widely used in offshore engineering practice. On the basis of mooring line statics, an explicit formulation of single mooring chain/wire rope stiffness coefficients and mooring stiffness matrix of the mooring system were derived in this article, taking into account the horizontal restoring force, vertical restoring force and their coupling terms. The nonlinearity of mooring stiffness was analyzed, and the influences of various parameters, such as material, displacement, pre-tension and water depth, were investigated. Finally some application cases of the mooring stiffness in hydrodynamic calculation were presented. Data shows that this kind of stiffness can reckon in linear and nonlinear forces of mooring system. Also, the stiffness can be used in hydrodynamic analysis to get the eieenfrequencv of slow drift motions.

Nonlinear identification of systems with parametric excitation

In this paper, the incremental harmonic balance nonlinear identification (IHBNID) is presented for modelling and parametric identification of nonlinear systems. The effects of harmonic balance nonlinear identification (HBNID) and IHBNID are also studied and compared by using numerical simulation. The effectiveness of the IHBNID is verified through the Mathieu-Duffing equation as an example. With the aid of the new method, the derivation procedure of the incremental harmonic balance method is simplified. The system responses can be represented by the Fourier series expansion in complex form. By keeping several lower-order primary harmonic coefficients to be constant, some of the higher-order harmonic coefficients can be self-adaptive in accordance with the residual errors. The results show that the IHBNID is highly efficient for computation, and excels the HBNID in terms of computation accuracy and noise resistance.

Third-order nonlinear optical adjusting behavior in azobenzene metal complexes

The third-order nonlinear optical(NLO)materials with stimuli-responsive properties have received extraordinary attention due to their controllable photophysical properties.In this work,two attractive metal complexes third-order NLO switches,which are far superior to congeneric optical switches in terms of their performance conversion,versatility,and fast response,were successfully designed and synthesized.The test of their third-order NLO properties proves that the metal complexes exhibit reverse saturable absorption and self-defocusing refraction.After light irradiation,the third-order NLO behavior turns quickly into self-focusing refraction.The relation between the molecular structures and the third-order NLO properties was investigated via1H nuclear magnetic resonance and ultraviolet-visible absorption.The results show that the metal ions have a significant influence on the NLO behavior and reveal the origin of third-order NLO properties via Z-scan determinations,pump-probe technology,and density functional theory calculations.These metal complexes can be used as third-order NLO switches with excellent fatigue resistance and broaden the application range of third-order NLO materials with adjustable performances.