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1.
Summary 1. From the epigeal part of the plantH. perforatum growing in the Dzhungarian Ala-Tau we have isolated the lignane eudesmin, the known alkaloids evoxine, flindersine, and 7-isopentenyloxy--fagarine, and the new alkaloids haplamine, glycoperine, and methylevoxine. It has been shown that haplamine has the structure of 6-methoxyflindersine, glycoperine the structure of 7-hydroxy-4,8-dimethoxyfuranoquinoline 7-O--L-rhamnopyranoside, and methylevoxine the structure of 4,8-dimethoxy-7-(2-hydroxy-3-methoxy-3-methylbutoxy)furanoquinoline.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 3, pp. 320–328, May–June, 1976.  相似文献   

2.
A preparative method for the synthesis of 9- (2,2,2-trifluoroethyl)-1,2,3,4,4a, 9a-hexahydro--carbolines by the action of alkali metal borohydrides in trifluoroacetic acid on 1,2,3,4-tetrahydro--carbolines was developed. The indicated trifluoroethyl derivatives can also be obtained by reaction of the same reagents with 1,2,3,4,4a,9a-hexahydro--carbolines, which are intermediates in the overall reduction-trifluoroethylation process.See [1] for a preliminary communication.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1383–1386, October, 1980.  相似文献   

3.
The design and function of novel supramolecular fluoroionophore/cyclodextrin (CyD) complex sensors for ion and molecule recognition in water are reviewed. For the crown ether fluoroionophore/-CyD complex, the dimerization of the fluoroionophore inside the -CyD is found to be selectively promoted by alkali metal ion binding, thereby resulting in metal-ion-selective pyrene dimer emission in water. This supramolecular function is successfully utilized in the design of a podand fluoroionophore/-CyD complex for sensing toxic lead ion in water. The boronic acid fluoroionophore/-CyD complex binds sugars and produces increased fluorescence emission in water. The response mechanism appears to be due to the suppression of the photoinduced electron transfer (PET) from pyrene donor to trigonal phenylboronic acid acceptor. This is a novel emission function provided by the boronic acid fluoroionophore/-CyD complex sensors in water.  相似文献   

4.
Zusammenfassung Es wird die Synthese von 2-(-Dialkylaminoacryloyl)cyclohexanonen beschrieben, uie durch Addition des Ketens an 2-Dialkylamino-methylencyclohexanone erhalten wurden.Außerdem wird die Darstellung von -Sultonen der 4-Hydroxy-2-dialkylamino-3,4-tetramethylen-3-buten-1-sulfonsäuren beschrieben, und zwar durch Reaktion des Sulfens, des Isosteren des Ketens, mit den vorher erwähnten 2-Dialkylamino-methylencuclohexanonen.
The synthesis of 2-(-dialkylaminoacriloyl)cyclohexanones by addition of ketene to 2-dialkylamino-methylenecyclohexanones is described.Also the preparation of 4-hydroxy-2-dialkylamino-3.4-tetramethylene-3-butene-1-sulfonic acid -sultones by reaction of sulphene with 2-dialkylamino-methylencyclohexanones is described.


Herrn Prof. Dr.F. Wessely mit den besten Wünschen zum 70. Geburtstag gewidmet.  相似文献   

5.
First experiments on the transmutation of long-lived129I and237Np using relativistic protons of 3.7 GeV are described. Relativistic protons generate in extended Pb-targets substancial neutron fluences. These neutrons get moderated in paraffin and are used for transmutation as follows:129I(n,)130I and237Np(n,)238Np. The isotopes130I (T 1/2-12.36 h) and238Np (T 1/2=2.117 d) were identified radiochemically. One can estimate the transmutation cross-section (n,) in the given neutron field as (129I(n,))=(10±2)b and (237Np(n,))=(140±30)b The experiments were carried out in November 1996 at the Synchrophasotron, LHE, Dubna, Russia. The investigation has been performed at the Laboratory of High Energies, JINR, Dubna.  相似文献   

6.
Two kinds of crystalline zirconium phosphate, - and -ZrP were prepared by direct method, and characterized by means of X-ray powder diffractometry, thermogravimetric analysis and pH titration. The total exchange capacity of -ZrP and -ZrP for Na+ ions determined by pH titration was 8.80 mmol/(g Zr(HPO4)2·6H2O) and 3.80 mmol/(g NH4ZrH(PO4)2·H2O), respectively. The thermodynamic equilibrium constant of exchange reactions on -ZrP and on -ZrP at 25.0°C is 2.5 and 1.1, respectively. Although UO 2 2+ in solution is more preferred by -ZrP than by -ZrP, the selectivity of -ZrP for UO 2 2+ decreases with decreasing pH value while less effect of pH on the amount of UO 2 2+ ions exchanged to -ZrP has been found. It is also interesting to find out that both H+ and NH 4 + ions in -ZrP can be replaced by UO 2 2+ ions existed in concentrated solution.  相似文献   

7.
Summary Under the influence of caustic alkalies, diffugenin (14-anhydrostrophanthidin) undergoes a complex irreversible change with the opening of the butenolide ring. The main product is a -hydroxy--lactone (lactol)-the stable tautomeric form of a -aldehydo acid. The existence of aldo-lactol tautomerism is confirmed by the preparation of derivatives of the and forms. The hypothesis has been put forward that the double bond at C14 in diffugenin and its derivatives readily undergoes autoxidation with the formation of epoxy compounds.Khimiya Prirodnykh Soedinenii, Vol. 4, No. 2, pp. 92–98, 1968  相似文献   

8.
A -spectrometric method has been developed for the assay of uranium in crude UF4, which is used as a secondary source of input material for producing nuclear grade U-metal at natural uranium conversion plants. The method makes use of a NaI (Tl) detector coupled with a multichannel analyzer. The 1 MeV -ray of238U is used for calibration. A method for the fabrication of uniform -assay calibration standards is also suggested, based on the results of this investigation. The calibration standards were prepared by soaking the matrix in uranium solution and then drying the whole material. The amount of238U in the crude UF4 sample was directly estimated by comparing the areas under the 1 MeV -ray peak of known calibration standards with the corresponding areas of the samples to be measured. 100 g each of the standard and the sample were counted. 5 crude UF4 samples were analyzed by this method. The uranium contents in these samples were found to be in the range of 12.2–28.7 g. To compare the -ray spectrometry results with a completely independent method, chemical analysis by potentiometry of all the samples was also done. The -spectrometric results were found to agree within ±18% with the chemical analysis results.  相似文献   

9.
Diffuse scattering IR spectroscopy was applied to study the adsorption and plasma-assisted catalytic conversion of methane (deuteromethane) on the surface of -alumina. It was found that CH4 adsorption sites on the -Al2O3 surface were formed by molecular and dissociative mechanisms under the action of an electric-discharge plasma at room temperature. As distinct from -radiolysis, plasma treatment leads to the formation of acetylene in addition to other hydrocarbon products, aluminum hydrides, and surface hydroxyl groups. Plausible mechanisms were proposed for plasma-assisted catalytic reactions in the -Al2O3–adsorbed CH4(CD4) system.  相似文献   

10.
Styrene (St)-acrylic acid (AA) copolymer plates were synthesized in the frames made of glass, aluminum (Al) and poly(difluoroethylene) (PDFE). Surface properties of the prepared copolymer plates were characterized with regard to critical surface tension ( C ), chemical components by IR analysis and surface energies (total energy, S ; dispersion force components, S d ; polar component, S p ; hydrogen bonding component, S h ) and the following results were obtained.The C values of the copolymer plates increased with AA content and also depended on the sort of the used frame. The increasing order of the C values of the copolymer plates corresponded to those of the used frames, namely, PDFE frame < Al frame < Glass frame.The prepared copolymer plates with low AA contents (ca. 10 mol%) were enriched in the AA moiety in the surface layer regardless of the kind of the used frame.The total and the individual components of the surface free energies of the copolymer plates were largely affected by the property of the used frame. The glass frame gave the plate with higher S h values suggesting preferential orientation of the polar site of AA component.  相似文献   

11.
An instrumental method for activation analysis based on multiparameter coincidence spectrometry is described. Practical considerations of our X- and - coincidence systems are presented. The main applications of geochemical interest are the non-destructive determinations of tin in granitic rocks and iridium in ultra-basic rocks. Some other applications to the activation analysis are proposed.  相似文献   

12.
Various water-pyridine mixtures have been selected in order to compare several of the most popular extrathermodynamic assumptions involved in the determination of the transfer activity coefficient of the proton, t(H+). Two techniques have been utilized for this purpose: voltammetry [study of the ferrocene, ferricyanide, or thallium(1) systems] and potentiometry at equilibrium (emf measurements of various galvanic cells, including liquid junctions and hydrogen electrode or silver electrode as a test electrode). The assumptions have been classified into various groups [e.g., t(Zp+)=t(Zq+) or t(X)=t(Y+)], and the values of t(H+) have been experimentally determined in each case. The results vary depending upon the basic assumption (several pH units); less important differences (e.g., 0.5 pH unit) occur within a given group, and this may be assigned to the nature of the reference species chosen. A simple model of solvation has been also examined; the application of the law of mass action to the corresponding equilibrium provides results close to the t(X) =t(Y+)type of assumptions which ultimately leads to most self-consistent results.  相似文献   

13.
The possibility of synthesizing silacyclobutane derivatives from haloalkylalkoxysilanes has been studied (with-chloropropylmethyldimethoxysilane and-chloropropyidimethylmethoxysilane as examples). The intramolecular cyclization of these compounds takes place only when polar solvents are used.  相似文献   

14.
    
Zusammenfassung Die Elektroimmundiffusion erlaubt bei G-monoclonalen Gammopathien die qualitative und semiquantitative Differenzierung von Paraund Normalproteinen der gleichen Immunglobulinklasse. Die exakte quantitative Bestimmung der nicht paraproteinämischen Komponente ist möglich bei genügend großem Unterschied in der elektrophoretischen Beweglichkeit beider G-Globuline. An Beispielen von G-Globulinbestimmungen in Normalserum und Seren von Patienten mit monoclonalen und polyclonalen Gammopathien werden Brauchbarkeit und Grenzen der Methode diskutiert.
Immunochemical differentiation of G-monoclonal and polyclonal gammopathies by electroimmuno-diffusion
Abnormal and normal G-globulins in G-monoclonal gammopathies can be distinguished qualitatively and semiquantitatively by electroimmuno-diffusion. The exact quantitative determination of the normal G-globulin is possible, only in cases with sufficiently different electrophoretic mobility between both components. Applicability and limits of the method are discussed regarding examples of G-globulin determinations in normal serum and in sera from patients with monoclonal and polyclonal gammopathies.
  相似文献   

15.
The changes in the surface properties of oxygen plasma-treated polyethylene films during ageing in various atmospheres (water, dry nitrogen gas, and hexane) were studied from the viewpoint of the interaction of the surface functional groups formed on the films and the ageing media. The XPS (x-ray photoelectron spectroscopy) and the SSIMS (static secondary ion mass spectrometry) spectra indicated the formation of polar groups containing oxygen such as C=O on the film surface. The changes in the critical surface tension (C) of the film with ageing time were largely affected by the ageing atmospheres: the C value of the film aged in water increased, and those of the films aged in nitrogen gas and hexane decreased with an increase in ageing time. These different tendencies among the ageing media could be understood reasonably with examining the surface free energy ratios (the total energy, S tot , the dispersion force component, S d / S tot , the polar component, S p / S tot , the hydrogen bonding component, S h / S tot ) of the films. The ageing in water of which L is large gave the films with higher S p / S tot values, suggeting that the overturn and/or the orientation of the polar groups toward the water phase occurred so as to minimize the discrepancy of the surface free energy between the polymer surface and water. On the other hand, the ageing in nitrogen gas and hexane media of which L are small gave the films with lower S p / S tot and S h / S tot values, suggesting the overturn and/or the orientation of the polar groups into the bulk polymer.  相似文献   

16.
The predictive accuracy for estimating infinite dilution activity coefficients by a modification of the UNIFAC method wherein the group interaction parameters were based on only data (referred to as -based UNIFAC) has been studied. Estimates and measured values were compared for six prototypical solutes in a series of homologous n-alkanes, l-alcohols and alkanenitrile solvents. Despite the fact that the interaction parameters were derived using only data, this approach still gave serious errors due to several inherent problems in the original UNIFAC model. Its performance is sometimes even poorer than that of the original UNIFAC method. For example for nitromethane in alcohols and p-dioxane in nitriles values predicted by the -based UNIFAC are essentially zero. The large errors for these systems are most likely due to inaccurate interaction parameters in the -based UNIFAC method.  相似文献   

17.
Summary Surface tension e of mercury in equilibrium with crystals (floating on its surface) of octacosane, 1-hexadecanol, 1-octadecanol, ethyl palmitate, benzophenone and azoxybenzene at 7° is almost equal to that at 23° (measured earlier); also the difference between the surface tension ( 0) of uncontaminated mercury and e (i. e., equilibrium surface pressure) is independent of temperature within the limits of the experimental error. This shows that the hypothesis making 0- e an analog of the vapor pressure of the solid is incorrect. The relation e= (=cohesion of the crystal,=thickness of the surface layer of mercury) is in agreement with the negligible temperature coefficient of e . The calculated is approximately 9 angstroems.
Zusammenfassung Die Oberflächenspannung e von Quecksilber im Gleichgewicht mit Kristallen (schwimmend auf der Oberfläche) von Octosane, 1-hexadecanol, 1-octodecanol, Äthylpalmitat, Benzophenon und Azoxylbenzol bei 7 °C ist nahezu gleich der bei23 °C gemessenen. Auch die Differenz der Oberflächenspannung von reinstem Quecksilber ( 0) und ( e), d. h. dem Gleichgewichtsobderflächendruck ist unabhängig von der Temperatur innerhalb der experimentellen Fehlergrenze. Dies zeigt, daß die Hypothese, nach der man 0- e in Analogie zum Dampfdruck des Festen betrachtet, unkorrekt ist. Die Beziehung e= (=Kohäsion des Kristalls,=Dicke des Oberflächenfilms auf Quecksilber) ist in Übereinstimmung mit dem vernachlässigbaren Temperaturkoefifzienten von e. Das berechnete beträgt ungefähr 9 Å.
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18.
From the roots ofHaplophyllum dauricum (L) G. Don., collected on the territory of the Uvur-Khangai aimak, Mongolian People's Republic, in the fruit-bearing stage have been isolated robustine, dictamnine, -fagarine, haplopine, skimmianine, 4-methoxy-N-methyl-2-quinolone, folimine, robustinine, and the new alkaloid daurine the structure of which has been established as 8-(,-dimethylallyloxy)-4-methoxy-N-methyl-2-quinolone.Institute of Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 1, pp. 73–76, January–February, 1984.  相似文献   

19.
More than one hundred undisturbed soil samples from Northern Venezuela and the islands of Margarita and Los Roques have been analyzed for137Cs,40K,238U and232Th by -ray spectroscopy. The specimens were taken from between 5–10 cm below the earth's surface. Thus, they are valid not only for the137Cs deposition studies but also for the estimation of the natural -ray dose from primordial radionuclides that form the terrestrial component. The concentration of40K was directly determined from its 1461 keV -ray, while those of137Cs,238U and232Th were performed using a -ray from one of their daughter radionuclides: the 661 keV -ray of137mBa for137Cs, the 1760 keV -ray of214Bi for238U and the 2620 keV -ray of208Tl for232Th. Finally, the concentration values were compared with those of global estimates.  相似文献   

20.
Summary A series of unfractionated and fractionated samples of polymethyl acrylate of different low molecular weights have been prepared by homogeneous solution. polymerization in dimethyl formamide in presence of , '-azo-(-cyano-n-valeric acid) as initiator under a variety of conditions. The number-average molecular weights have been determined by end-group titrations and vapour pressure osmometry. The following []-M relationships for polymethyl acrylate have been obtained.[] = 33.5 x 10–5M0.63 for unfractionated samples in benzene at 25 °C. [] = 3.89 x 10–5M0.843 for fractionated samples in benzene at 35 °C.With 2 tables  相似文献   

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