A full-scale tracing study of “ghost peaks” encountered in impurity analysis of budesonide based on experimental operation inspection-liquid chromatography/mass spectrometry fingerprint-mechanism based stress studies integrated strategy

Budesonide is an active pharmaceutical ingredient used in various dosage forms of finished products for the treatment of asthma. During the process of drug development, unbiased analysis of related substances is of utmost significance for both pharmaceutical research and quality control purposes. In this work, the official method documented in the United States Pharmacopoeia was selected to determine the related substances of budesonide considering the pros and cons of critical chromatographic parameters, compared to the European Pharmacopoeia. In doing so, several unpredictable interference peaks, namely “ghost peaks”, were observed occasionally during analysis. A strategy that integrated information derived from experimental operation inspection, liquid chromatography/mass spectrometry fingerprint analysis, and mechanism-based stress studies was then proposed for comprehensively and quickly exploring those non-degradable and degradable peaks. Some ghost peaks were found to originate from nylon syringe filter, illumination, and alkali borosilicate glass high-performance liquid chromatography vials. Besides, degradation pathways under alkaline conditions were also unraveled through liquid chromatography-mass spectrometry qualitative analysis. Overall, an optimization of the analytical methodology based on the United States Pharmacopoeia for its application in impurity analysis of budesonide and corresponding formulations was carried out with the design of experiments, by which “ghost peaks” could be suppressed or prevented. The results obtained herein are not only crucial to studies on budesonide's stability or degradation kinetics but also contribute to clarifying the impurity research of other drugs.     

针对多散斑图的差分压缩鬼成像方案研究

鬼成像方案实现所需设备、成像的质量以及成像所花的时间是决定鬼成像技术可实用化的重要因素. 本文提出一种针对多散斑图的差分压缩鬼成像方案. 该方案通过连续探测多个独立的散斑图, 降低了热光鬼成像方案对探测器高时间分辨力的要求; 通过采用差分方法, 抑制了背景噪声和其他噪声源的干扰; 通过使用压缩感知重建算法, 有效地降低了鬼成像所需时间并同时提升成像的质量. 数值仿真结果表明, 对于二灰度“N” 图, 本方案在8000次的采样情形下与多散斑图鬼成像方案35000次采样的结果相比, 均方误差降低了96.9%、峰值信噪比提升15.1 dB. 对于八灰度“Pepper”图, 本方案与多散斑图鬼成像方案相比, PSNR提升11.4 dB. 本方案可降低探测设备的要求、提高成像质量、降低重建时间, 具有广阔的应用前景.     

Phase modulation pseudocolor encoding ghost imaging

We present a ghost imaging scheme that can obtain a good pseudocolor image of black-and-white objects.The essential idea is to use a multi-wavelength thermal light source and the phase modulation pseudocolor encoding technique,which overcomes the disadvantages of other methods involved spatial filtering.Therefore,the pseudocolor ghost image achieved by this imaging scheme is better than that obtained by other methods in terms of brightness,color,and signal-tonoise ratio.     

Non-lane-based full velocity difference car following model

In order to describe car following behavior in real world, this paper presents a non-lane-based car following model by incorporating the effects of the lane width in traffic. The stability condition of the model is obtained by using the linear stability theory. And numerical simulation is carried out to validate the analytic results. The property of the model is investigated, and it is found that the proposed model can describe the phase transition of traffic flow and estimate the evolution of traffic congestion. The results implied that incorporating the lane width effects in car following model not only stabilize traffic flow and suppress the traffic jam, but also lower critical headway and increase capacity. Thus, the lateral separation effects greatly enhance the realism of car following models.     

A GHOST FLUID BASED FRONT TRACKING METHOD FOR MULTIMEDIUM COMPRESSIBLE FLOWS

Recent years the modify ghost fluid method （MGFM） and the real ghost fluid method （RGFM） based on Riemann problem have been developed for multimedium compressible flows. According to authors, these methods have only been used with the level set technique to track the interface. In this paper, we combine the MCFM and the RGFM respectively with front tracking method, for which the fluid interfaces are explicitly tracked by connected points. The method is tested with some one-dimensional problems, and its applicability is also studied. Furthermore, in order to capture the interface more accurately, especially for strong shock impacting on interface, a shock monitor is proposed to determine the initial states of the Riemann problem. The present method is applied to various one- dimensional problems involving strong shock-interface interaction. An extension of the present method to two dimension is also introduced and preliminary results are given.     

A polynomial time interior–point path–following algorithm for LCP based on Chen–Harker–Kanzow smoothing techniques

$$O\sqrt{n}L$$ ); otherwise, the complexity bound is O(nL). The relations between our search direction and the one used in the standard interior-point algorithm are also discussed. Received September 9, 1996 / Revised version received December 22, 1997? Published online March 16, 1999     

带有随机干扰和确定投资回报风险过程下的一些分布

我们考虑既带有随机干扰又带有确定投资回报的风险过程, 得到了破产前瞬间盈余的分布$F_{\delta}(u,x)$及破产前瞬间盈余和破产时赤字的联合分布$H_{\delta}(u,x,y)$所满足的积分表达, 连续性及二次连续可微性和积分--微分方程. 同时, 只有随机干扰的风险模型下的破产前瞬间盈余的分布及破产前瞬间盈余和破产时赤字的联合分布所满足的性质也被得到. 已有文献中的诸多有关结果均可以通过令我们结论中的某些参数特殊化为零而得到.     

A path following method for box-constrained multiobjective optimization with applications to goal programming problems

We propose a path following method to find the Pareto optimal solutions of a box-constrained multiobjective optimization problem. Under the assumption that the objective functions are Lipschitz continuously differentiable we prove some necessary conditions for Pareto optimal points and we give a necessary condition for the existence of a feasible point that minimizes all given objective functions at once. We develop a method that looks for the Pareto optimal points as limit points of the trajectories solutions of suitable initial value problems for a system of ordinary differential equations. These trajectories belong to the feasible region and their computation is well suited for a parallel implementation. Moreover the method does not use any scalarization of the multiobjective optimization problem and does not require any ordering information for the components of the vector objective function. We show a numerical experience on some test problems and we apply the method to solve a goal programming problem.     

The photomagneton B(3) and longitudinal ghost field B(3) of electromagnetism

The concepts are introduced of the longitudinal ghost fieldB ⁽³⁾ and photomagnetonB ⁽³⁾) of electromagnetism:B ⁽³⁾ = B⁽³⁾ =B⁽⁰⁾/, whereB ⁽⁰⁾ is the magnetic flux density amplitude and the angular momentum operator of a photon beam. The major implication is that the individual photon hasthree degrees of polarization, the longitudinal one being accompanied by the ghost fieldB ⁽³⁾ which has no energy or linear momentum, and is generated from the angular momentum of the photon.     

两次双波长分光光度法测定铅和汞

基于卟啉试剂ＴＡＰＰ与Ｐｂ￣（２＋）、Ｈｇ￣（２＋）在碱性介质中有灵敏的显色反应，建立了两次双波长分光光度法同时测定Ｐｂ、Ｈｇ的新方法，摩尔吸光系数分别为４．５９×１０￣５和４．３２×１０￣５ｍｏｌ￣（－１）·ｃｍ￣（－１）·Ｌ；可同时测定１：５～１０：１范围内的Ｐｂ和Ｈｇ，用于水中Ｐｂ和Ｈｇ的同时测定，结果满意。