Breather and double-pole solutions of the derivative nonlinear Schrödinger equation from optical fibers

The derivative nonlinear Schrödinger (DNLS) equation, which governs the propagation of the femtosecond optical pulse in a monomodal optical fiber, is analytically studied in this Letter. Breather and double-pole solutions are derived from the two-soliton solution with the choice of parameters. It is found that the parameters in the DNLS equation cannot only control the phase and propagation direction of the breather and double pole, but also influence the interaction period of the breather. Elastic collisions between a breather and a dark/anti-dark soliton are studied by the qualitative analysis and graphical illustration. The stability of the breather and double-pole solutions is also analyzed.     

Simultaneous Determination of Two Synthetic Dyes Erytrosine and Sunset Yellow in a Pharmaceutical Syrup By First Derivative Visible Spectrophotometry

ABSTRACT.

A rapid first derivative spectrophotometric method for simultaneous determination of two synthetic dyes, erytrosine (E 127) and sunset yellow (E 110), in a mixture is proposed. The procedure does not require any separation step. The method was applied for determining the two compounds in a pharmaceutical syrup. Good linearity, accuracy, precision and selectivity were found, and the method is proposed for routine quality control purposes.     

A WAVELET TRANSFORM AND ITS APPLICATION TO SPECTROSCOPIC ANALYSIS

ABSTRACT

An introduction to the wavelet transform and its applications in spectroscopy analysis are presented. Owing to the property of the dual localization both in time and in frequency domains, the wavelet transform exhibits several useful characteristics. With the wavelet transform a signal can be decomposed into series of contributions according to the frequency difference, these contributions are respectively called discrete approximations and discrete details. By applying certain treatment to the discrete approximations (the low frequency part) or the discrete details (the high frequency part), a part of the original signal within a certain frequency range can be obtained. The wavelet transform has been applied in various fields of the analytical chemistry, including removal of high frequency noise, information extraction, resolution of overlapping signals, and data compression etc. Research concerning application in analytical chemistry are introduced in respect of photoacoustic spectroscopy, EXAFS spectrum, NMR analysis, and Raman spectrum.     

The Pfaff/Cauchy derivative identities and Hurwitz type extensions

More than 200 years ago, Pfaff found two generalizations of Leibniz’s rule for the nth derivative of a product of two functions. Thirty years later Cauchy found two similar identities, one equivalent to one of Pfaff’s and the other new. We give simple proofs of these little-known identities and some further history. We also give applications to Abel-Rothe type binomial identities, Lagrange’s series, and Laguerre and Jacobi polynomials. Most importantly, we give extensions that are related to the Pfaff/Cauchy theorems as Hurwitz’s generalized binomial theorems are to the Abel-Rothe identities. We apply these extensions to Laguerre and Jacobi polynomials as well. Dedicated to Dick Askey on the occasion of his 70th birthday. 2000 Mathematics Subject Classification Primary—05A19; Secondary—33C45     

透光率导数光谱与吸光度导数光谱的比较

研究了糖精钠在220－260nm的1－6阶透光率导数光谱和吸光度导数光谱，透光率导数光谱的灵敏度大大高于吸光度导数光谱，但其抗干扰能力比吸光度导数光谱差，两者特征峰强度与浓度的线性关系接近。     

导数吸光光度法快速测定药物的体外经皮渗透量

用改进了的Franz扩散室（L.G.Y扩散室）处理给药贴片和鼠皮，设定取样时段，吸取接受室中溶液，用导数吸光光度法测定给药经皮渗透量。所得结果与高效液相色谱法（HPLC）一致，而效率约为原法（使用未改进的Fuanz扩散室，用HPLC测定）的10倍。     

用四(4-三甲铵苯基)卟啉作显色剂导数分光光度法同时测定钴镉铅的研究

本文以四(4-三甲铵苯基)卟啉作显色剂,在阳离子表面活性剂CPB存在下的pH9.8缓冲溶液中,利用三阶导数分光光度法,对钴、镉、铅的同时测定进行了详细研究。本方法测定灵敏度较高,对合成样品进行测定,结果令人满意。     

用2-(4,5-二甲基-2-噻唑偶氮)-5-二甲氨基苯甲酸作显色剂导数光度法同时测定钴和镍

本文研究了用2-(4,5-二甲基-2-噻唑偶氮)-5-二甲氨基苯甲酸(简称DMTAMB)作显色剂,在乙醇介质中,利用一阶导数消除钴(Ⅲ)和镍(Ⅱ)彼此间的干扰,对镍矿石中微量钴和镍进行同时测定,结果满意。     

系数倍率导数光谱法定量测定纤维上染料

本文介绍了用系数倍率导数光谱法同时测定黄棕色涤纶上的分散黄ＲＧＦＬ，分散棕２ＲＬ，分散红Ｓ－ＢＷＦＬ的配比。这三种染料吸收峰重叠大，用该法可以完全消除彼此的干扰而不用分离，测得三种染料的配比与工艺配方中的比例一致，结果准确，可靠，回收率较好。这个方法操作简便，快速，可用于纵上染料的测定。