硫酸铵存在下碘化物-4-氨基安替吡啉-丙醇体系萃取分离镉1

研究了在硫酸铵存在下,碘化物-4-氨基安替吡啉体系萃取镉的行为以及丙醇水溶液的分相条件。实验表明,丙醇作为萃取溶剂能萃取中性离子缔合物。调节溶液pH=2.0—3.0,该体系能使Cd2 从常见过渡元素Fe~(2 )、Co~(2 )、Mn~(2 )、Ni~(2 )、Zn~(2 )的混合液中分离出来。     

Design of a multi-channel dropping segmenter for liquid-liquid extraction continuous flow-injection analysis

A simple dual-channel dropping segmenter was used for the simultaneous introduction of aqueous solutions of a sample and an organic analytical reagent directly into a continuous flow of an immiscible organic solvent. Droplets of precisely defined volume of the homogeneous reaction mixture are formed at the junction of the inlet capillary system. Reaction and extraction take place simultaneously in the individual segments of the aqueous phase during the transport through the reaction/extraction coil. An analytical signal is measured by an “on-tube” fast-reading spectrophotometric detector and processed mathematically. The applicability of the method is demonstrated with the determination of Cu(II) ions with tetramethylene-dithiocarbamate in neutral medium in 0.1 M ammonium acetate buffer.     

聚乙二醇-钍试剂-硫酸钠体系中非有机溶剂萃取光度法测定铁

本文研究了铁（Ⅲ）－ＰＥＧ（聚乙二醇－２０００）－钍试剂－Ｎａ２ＳＯ４体系的析相光度法并应用于测定Ｆｅ（Ⅲ），最适酸度为４．６（ＮａＡｃ－ＨＡｃ）缓冲溶液，其络合物的最大吸收位于５６６ｎｍ，表观摩尔吸光系数为８．０６×１０３Ｌ·ｍｏｌ－１·ｃｍ－１。Ｆｅ（Ⅲ）浓度在０—３０μｇ·ｍＬ－１范围内服从比耳定律，该方法用于发样中铁的测定，获得了满意结果     

Implicit Regularization and Renormalization of QCD

We apply the Implicit Regularization (IR) technique in a non-abelian gauge theory. We show that IR preserves gauge symmetry as encoded in relations between the renormalization constants required by the Slavnov–Taylor identities at the one-loop level of QCD. Moreover, we show that the technique handles divergencies in massive and massless QFT on equal footing.     

Extraction of cellulose and preparation of nanocellulose from sisal fibers

In this work a study on the feasibility of extracting cellulose from sisal fiber, by means of two different procedures was carried out. These processes included usual chemical procedures such as acid hydrolysis, chlorination, alkaline extraction, and bleaching. The final products were characterized by means of Thermogravimetric Analysis (TGA), Infrared Spectroscopy (FTIR), X-Ray Diffraction (XRD), Differential Scanning Calorimetry (DSC) and Scanning Electronic Microscopy (SEM). The extraction procedures that were used led to purified cellulose. Advantages and disadvantages of both procedures were also analyzed. Finally, nanocellulose was produced by the acid hydrolysis of obtained cellulose and characterized by Atomic Force Microscopy (AFM).     

Spot Size Technique: A Theoretical Approach To Optimize Dispersion Compensated

Using a spot size based optimization technique, a bend loss versus dispersion diagram has been obtained theoretically for the most widely used step-index disper sion compensated optical fibers (DCF). The Rayleigh scattering loss can be incorpo rated with bend loss to calculate figure of merit (FOM), thus giving an FOM versus dispersion curve on a single diagram. The plot of the FOM-dispersion curve on a single diagram is useful from the designer's point of view, as it provides a quick reference for choosing the best suitable DCF, which should have large negative dispersion as well as maximum possible value of FOM. The effect of fiber manufac turing losses such as absorption loss on the maximum value of FOM has also been estimated.     

Decomposition through formalization in a product space

When an optimization problem is posed in a product space it is classical to decompose this problem. The goal of this paper is to show how such an approach can be used when the problem to be solved is not naturally posed in a product space. By associating systematically to this problem an equivalent one posed in ann-fold cartesian product space, we obtain by decomposition of the latter both a splitting of operators and a desintegration of constraints for the former. Applications to three rather classical mathematical programming problems are given.     

Separation with Supercritical Gases: Practical Applications

Extraction with supercritical gases combines, to a certain extent, the characteristics of both distillation and extraction; the term “destraction” is therefore proposed for this method of separation. The principles of the method are illustrated in this article by a series of color photographs comparing extraction and destraction. Of the practical uses of this new method may be mentioned the separation of cod-liver oil into 50 fractions, each differing in saponification value and iodine number, by means of supercritical ethane and, in particular, the decaffeination of raw coffee with supercritical carbon dioxide.     

Extraction chromatography of cobalt and some other metals an silica treated with a mixture of Aliquat 336 and nitroso-R-salt

Summary It was found that cobalt is strongly retained on silica treated with a mixture of Aliquat 336 and nitroso-R-salt and can be separated by column extraction chromatography from cadmium, lead, zinc, mangan, nickel, copper and iron (III) which were eluted with 0.05M solution of perchloric acid. Cobalt was quantitatively eluted with 1 M perchloric acid and subsequently determined by atomic absorption spectrophotometry Cobalt was also concentrated from very dilute aqueous solutions by frontal analysis on small columns packed with the same sorbent, eluted together with a stationary phase with methanol and subsequently determined spectrophotometrically at 466nm; in this way a 500 fold concentration of cobalt was achieved permitting the determination of cobalt at the ppb level.