淀粉共聚物的合成与应用

本文介绍了淀粉共聚物的合成方法,包括自由基引发、阴离子引发和其它引发方法等;以及共聚物的应用范围:增稠剂、絮凝剂、粘合剂、吸水剂和上浆剂等.     

微波技术在有机合成中的应用

评述了微波加热技术在有机合物的烃基化，酯化和皂化，磺化，烯烃加成，Ｄｉｅｌｓ－Ａｌｄｅｒ缩合，氧化，环化与开环及重排等反应中的应用，参考文献７３篇。     

The Polarographic Determination of Fluvoxamine Maleate

Abstract

In this study, the polarographic behaviour and the optimum polarographic conditions for the determination of fluvoxamine using DC, DP and SIAP techniques are described based on the reduction on the DME. The experiments were conducted in the aqueous supporting electrolyte containing 0.2 M KCI, 20% ethanol (v/v) and 0.2 M buffer solution. Single waves were obtained at various pH values. The limiting currents were decreased and E_1/2 values were linearly shifted to more negative potentials with an increase of pH. The system was irreversible at both the acidic and the basic medium and was controlled by adsorption at pH 4.2 and by diffusion at pH 8.03. The variation of the limiting current against temperature was found to be 1.1 μA°C. Good calibration relations were obtained for DC (direct current), DP (differential pulse) and SIAP (superimposed increasing amplitude pulse) techniques. The determination of fluvoxamine in a pharmaceutical preparation, Faverin® Tablets containing 50 mg of fluvoxamine, were tested. The results were compared to those of UV-spectrophotometric method. In the analysis of a single 50 mg tablet, the relative standard deviation (S_rel) are found to be between ±0.5 and ±1.0 for the techniques employed for filtered and unfiltered solutions. The polarographic techniques used for the determination of fluvoxamine seem to be accurate, rapid and practical. Therefore, the suggested method may be promising in the routine analysis.     

基于正交频分复用无源光网络的动态带宽分配算法研究

介绍了一种应用于未来大容量、多业务接入场景下的称为光正交频分复用无源光网络的下一代接入网技术,并提出了一种基于此结构的称为基于服务质量需求的固定周期流水线轮询动态带宽分配算法.该算法通过应用二级带宽分配机制、带宽预申请机制和最小带宽申请优先原则等方法,有效地保障了在大容量、多业务接入场景下各个业务不同的服务质量需求.为...     

Synthesis, application and flame retardancy mechanism of a novel flame retardant containing silicon and caged bicyclic phosphate for polyamide 6

A novel flame retardant containing silicon and caged bicyclic phosphate groups, tri(2,6,7-trioxa-1-phosphabicyclo[2.2.2]octane-1-oxo-4-hydroxymethyl) phenylsilane (TPPSi) was successfully synthesized. The chemical structure of TPPSi was characterized by FTIR, ¹H NMR and ³¹P NMR. The application of TPPSi (25 wt%) as a flame retardant in polyamide 6 (PA6) not only gains satisfied flame retardancy and smoke suppression, but also retains the high toughness and inherent appearance of pure PA6. The influence of TPPSi on the decomposition pathway of PA6 was discussed based on TG-FTIR and FTIR analysis. The interaction between TPPSi and PA6 at high temperature alters the decomposition pathway of PA6 resulting in the formation of the residue containing phosphorus and silicon. The heat and smoke release behaviors at different external heat fluxes were measured by cone calorimeter, and the fire residue was analyzed by SEM-EDX. The condensed phase action resulting from the barrier effect of residue is proposed to be the major flame retardancy mechanism of TPPSi in PA6, with the fuel reduction action as the minor.     

我国固体无机化学的研究进展

综合介绍了建国５０年来，尤其是近２０年来我国固体化学研究领域所取得的进展，阐述了该领域在合成方法上的更新以及不断向信息、能源、环保等应用领域提供的各种新材料。     

经济活动中的几个数学模型及其应用

随着市场经济的不断发展，利用数学知识解决实际问题变得越来越重要。本文重点探讨了经济活动中几个非常实用的数学模型的构建与应用问题。     

Sensitivity analysis of machine repair problems in manufacturing systems with service interruptions

This paper models a manufacturing system consisting of M operating machines and S spare machines under the supervision of a group of technicians in a repair facility. Machines fail according to a Poisson process, and the repair (service) process of a failed machine may require more than one phase. In each phase, service times are assumed to be exponentially distributed but may be interrupted when the repair facility encounters unpredictable breakdowns. Two models of manufacturing systems are considered. In the first model, technicians repair failed machines at different rates in each phase. In the second model, a two-phase service system with differing numbers of technicians is considered. Profit functions are developed for both models and optimized by a suitable allocation of the number of machines, spares, and technicians in the system. Finally, a sensitivity analysis (see Cao [X.R. Cao, Realization Probabilities: The Dynamics of Queuing Systems, Springer-Verlag: London, 1994; X.R. Cao, The relations among potentials, perturbation analysis, and Markov decision processes, Discrete Event Dynam. Syst.: Theory Applicat. 8 (1998) 71–87]) is performed to provide an approach that quantifies the impact of changes in the parameters on the profit models.     

An inventory control system for spare parts at a refinery: An empirical comparison of different re-order point methods

Inventory control of spare parts is essential to many organizations, since excess inventory leads to high holding costs and stock outs can have a great impact on operations performance. This paper compares different re-order point methods for effective spare parts inventory control, motivated by a case study at a large oil refinery. Different demand modeling techniques and inventory policies are evaluated using real data.     

Creep behaviour study of virgin and service exposed 5Cr–0.5Mo steel using magnetic Barkhausen emissions technique

Creep damage behaviour of water quenched 5Cr–0.5Mo steel has been studied using magnetic Barkhausen emissions (MBE) technique. The results were compared with the materials having same composition but used in service for 15 years to demonstrate the potentiality of the magnetic technique for in-situ evaluation of extent of creep damage of components. The rms voltage of magnetic Barkhausen signal for the virgin sample decreased at the initial stage of the expended creep life where new carbides are formed. As soon as the growth of the carbides took place at the expense of the smaller ones, MBE voltage started increasing due to the decrease of pinning density. However, in case of 15 years of service exposed sample, growth of carbides already took place and hence MBE voltage increased even during the initial stage of laboratory creep testing. As soon as the void started forming in the samples (both for virgin and service exposed one), the rate of increase of MBE voltage started decreasing. The formations of such cavities were observed through SEM micrograph analysis.