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991.
In this paper, the surface imprinted cross-linked polystyrene beads were prepared via suspension polymerization with styrene (St), divinylbezene (DVB), polyvinyl alcohol (PVA1788),the mixture of Span 85 and xylene or the mixture of Span 85 and paraffin as monomer,cross-linking agent, dispersion stabilizer and templates, respectively. The results indicate that there are dense cavities on the surface of beads, and the diameter and density of cavity are related with the composition and amount of emulsion template. The forming mechanism of cavity from thermodynamics and dynamics was proposed.  相似文献   
992.
993.
A method has been developed in which the DNA of leukocytes (as the buffy coat from blood) is isolated in the form of its constituent deoxynucleotides. The steps in this method are as follows: (1) lyse the leukocytes with sodium dodecyl sulfate (SDS) and enzymatically digest the proteins and RNA, (2) remove the SDS on a non-polar adsorbent (Bio-Beads SM-4) and then trap the DNA on a quaternary amine silica cartridge, (3) wash the column with 1 M NaCl-buffer, (4) digest the DNA on the column with staphylococcal nuclease and (5) elute the digested DNA with 0.5 M NaCl-buffer and digest it further with bovine spleen phosphodiesterase II to deoxynucleotide-3′-monophosphates. From a 40-μl sample of butty coat was obtained 126 ± 14 μg (two experiments, eight sample total) of deoxynucleotides. Reversed-phase high-performance liquid chromatography, which removed the added enzymes, showed only peaks for deoxynucleotides. For comparison, the amount of deoxynucleotides obtained from the leukocytes by an automated phenol extraction procedure was 101 ± 5.4 μg (one experiment in triplicate).  相似文献   
994.
    
Kinetics of the bis(2,2,6,2-terpyridine) iron(II)-cobalt(III) electron transfer reaction in sulfuric acid medium has been studied using stopped-flow spectrophotometry. The reaction is first order both in substrate and oxidant. Hydrogen ions accelerate the reaction, whereas bisulfate ions retard. A suitable mechanism is proposed considering Co3+, CoSO 4 + and Co(SO4) 2 as the reactive oxidizing species.
(2,2,6,2-)(II)(III) . , , . , -. , Co3+, CoSO4 + Co(SO4)2 .
  相似文献   
995.
The possibility has been shown of using IR spectroscopy in the investigation of the changes in the polysaccharide component of wood in the process of acid hydrolysis. The method of determining the relative optical density (ROD) was used for the quantitative evaluation of the changes in the functional groups of the lignocellulose.Deceased.Siberian Scientific Research Institute of Cellulose and Board, Bratsk. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 683–687, September–October, 1990.  相似文献   
996.
    
The reactions of benzoxazolinone and benzoxazolinethione with alkyl -chlorovinyl ketones have been studied. The reaction products are N-(-acylvinyl)benzoxazolinones and N-(-acylvinyl)benzoxazolinethiones. The reaction of alkali-metal salts of benzoxazolinone with alkyl -chlorovinyl ketones leads to the opening of the oxazolinone ring. The structures of the compounds synthesized have been studied by IR, mass, and PMR spectroscopy.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 507–511, July–August, 1983.  相似文献   
997.
Summary On the basis of IR, PMR, and mass spectra and chemical transformations, the alkaloid kesselringine isolated from the epigeal parts ofColchicum kesselringii Rgl. has been shown to have the structure of 2,11-dihydroxy-12-methoxyhexahydro-1,12-epoxyhomoproaporphine with the R absolute configuration at the C6a atom.V. I. Lenin Tashkent State University. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 350–354, May–June, 1976.  相似文献   
998.
Summary Two new analytical techniques are described. The so-called injection technique operates on evaluating a dynamic concentration signal as a result of following the concentration change in a certain part of a flow-through channel after injecting a sample or reagent at a small volume into the current of an appropriate solution flowing at a constant rate.The second technique, the programmed coulometric titration technique, also uses the flow-through channel principle; that means this novel technique allows the more precise titrimetric way of analysis in flowing solutions. In the case of both techniques potentiometric and voltammetric detectors were involved. Several examples proved the multifold advantages of these techniques for environmental analysis.
Neue elektroanalytische Verfahren für die Umweltanalyse
Zusammenfassung Zwei neue Methoden werden beschrieben. Die sog. Injektionstechnik wertet ein dynamisches Konzentrationssignal aus, das sich aus der Änderung in einem Durchflußkanal ergibt, wenn Probe oder Reagens in kleinen Volumina in einen konstant fließenden Flüssigstrom injiziert werden. Das zweite Verfahren, die programmierte coulometrische Titration, erlaubt die Anwendung der genaueren titrimetrischen Technik auf fließende Lösungen. Bei beiden Methoden werden potentiometrische und voltammetrische Detektoren verwendet. Mehrere Beispiele zeigen die vielfachen Vorteile dieser Verfahren bei der Anwendung auf die Analyse von Umweltmaterial.
Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria  相似文献   
999.
The exchange reaction of D2 with OH groups of HY zeolites was followed both in the solid and gas phase by IR and MS. The rates of D2–OH and D2–H2 exchange increase considerably with dehydroxylation of the sample. The active centers are probably vacancies formed by removal of oxygen from the lattice, they catalyze the dissociation of D2. Dehydroxylation of the sample is accompanied by the formation of 3 740 cm–1 hydroxyls, whose exchange with D2 is slower than that with other OH groups and which affect the kinetics in the gas phase.
D2 OH HY - O2–OH O2–H2 . , , , O2. OH, 3740 –1, , OH .
  相似文献   
1000.
Heterogeneous-homogeneous decomposition of HNO3   总被引:1,自引:0,他引:1  
In contrast to ZSM zeolites impregnated with V5+ salts, catalysts prepared by adding V3+ salts during zeolite synthesis exhibited (even when transformed into cristobalite by oxidative activation) higher selectivity to furane in the oxidation of butadiene. Non-oxidative activation preserved the zeolitic structure and increased both the total activity and the selectivity to furane.
ZSM, V5+, V3+ ( ) . , , .
  相似文献   
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