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1.
Summary The interaction between cyclodextrin and the drug (1R,2S,3S,4S)-(5Z)-7-(3-((phenylsulfonyl)amino)bicyclo[2.2.1]hept-2-yl)hept-5-enoic acid ((+)-S-145), was studied using -, -, and -cyclodextrin bonded-phase columns. Retention behavior of (+)-S-145 on these columns revealed that the strength of inclusion was -cyclodextrin. Interaction between -cyclodextrin and (+)-S-145 was found to increase as the proportion of carboxylic ion in the (+)-S-145 molecule increased. Comparison of binding capacities of these bondedsilica gels obtained by frontal analysis and surface coverage indicated that availability of the immobilized - and -cyclodextrin was 20–25%. The synthesized -cyclodextrin bonded-phase column was superior to that of commercial columns in terms of chiral separation of (±)-S-145. A typical usage of the -cyclodextrin column is discussed for separation of (±)-S-145 in plasma samples.  相似文献   

2.
A New Gamma-Ray Spectrum Catalog for PGAA   总被引:1,自引:0,他引:1  
A major obstacle to the use of the prompt gamma activation analysis (PGAA) method has so far been the lack of a suitable library. Therefore, new measurements have been performed at the PGAA facility at Budapest Research Reactor (BRR) in order to create a prompt -ray catalog for qualitative and quantitative analysis. Prompt -ray energies and associated k 0-factors have been determined by internal standardization. The resulting catalog contains prompt -ray data from neutron capture and other reactions such as (n,), and decay -ray data from short-lived reaction products. Data have been measured for nearly all stable elements, from hydrogen to uranium. Generally, data for several isotopes are given, to enable isotopic analysis as well.  相似文献   

3.
Summary A gas-chromatographic technique for a rapid separation of fission iodine or bromine from the other elements formed in nuclear fission was developed. Recoil-formed, volatile methyl bromide and methyl iodide were isolated within 1 min after the end of irradiation. An extension of this technique to other elements and to other nuclear reactions should be possible.The -ray spectra of both halogen fractions were measured. A dominating -ray at 0.79 MeV and a weaker -ray at 0.51 MeV were assigned to 88Br (half life 16 sec). No -ray could be unambiguously attributed to 137I (24 sec), a fact which makes unlikely the presence of highly intensive peaks in the -ray spectrum of this isotope. Further details of the spectra are discussed.
Zusammenfassung Eine gaschromatographische Methode zur schnellen Isolierung von Spaltjod oder Spaltbrom aus dem Gemisch der bei der Kernspaltung entstehenden Elemente wurde entwickelt. Mittels Spaltrückstoß gebildetes, flüchtiges Methylbromid oder Methyljodid wurde innerhalb 1 min nach Bestrahlungsende isoliert. Die Methode sollte auf andere Elemente und andere Kernreaktionen übertragbar sein.-Spektren der beiden Halogenfraktionen wurden gemessen und ergaben für 88Br (Halbwertszeit 16 sec) eine dominierende Linie bei 0,79 MeV und eine schwache Linie bei 0,51 MeV. In der Jodfraktion wurde keine -Linie beobachtet, die man eindeutig 137J (24 sec) hätte zuordnen können, was sehr intensive Peaks im Spektrum dieses Isotops unwahrscheinlich macht. Weitere Einzelheiten der Spektren werden diskutiert.


Dedicated to Prof. Dr. F. Strassmann on his 65th birthday.  相似文献   

4.
TI(III) oxidation of cellobiose in the presence of H2SO4 in aqueous acetic acid is first order in each reactant and is acid catalyzed. TI(OAc) 2 + is the active species. Products identified are gluconic acid and glucose. A mechanism consistent with the temperature, solvent, acidity and salt effects is been proposed.
TI(III) H2SO4 . TI(OAc) 2 + . . , , , .
  相似文献   

5.
Calcium chromite, CaCr2O4, was prepared and its purity and stoichiometry were ascertained by chemical analysis and X-ray diffraction methods. The thermal diffusivity, specific heat capacity and thermal conductivity of calcium chromite were measured by Laser Flash method using an Ulvac-Sinku Riko TC-3000 series instrument in the temperature range of 298 to 1100 K. The heat capacity data were utilised to calculate the thermodynamic parametersenthalpy increments, entropy increments and free energy increments—in the above temperature range.
Zusammenfassung Kalziumchromit, CaCr2O4, wurde hergestellt und seine Reinheit und stöchiometrische Zusammensetzung mit Hilfe chemischer Analyse und Röntgendiffraktionsmethoden ermittelt. Anhand eines Ulyac-Sinku Riko TC-3000 Gerätes wurde mit Laser Flash Verfahren die Temperaturleitfähigkeit, die spezifische Wärmekapazität und die Wärmeleitfähigkeit von Kalziumchromit im Temperaturbereich 298–1100 K bestimmt. Die Wärmekapazitätsdaten wurden zur Berechnung der thermodynamischen Größen (Enthalpie-, Entropie-, Freie Energieänderung) in obigem Temperaturbereich benutzt.

CaCr2O4, . , - TC-3000, 298–1100K , . , , .
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6.
A new approach for the determination of elemental uranium in uranium bearing ore, using high resolution -ray spectrometry, was applied. Using a variant of the enrichment technique an agreement of better than 1% has been obtained between -ray measurement results and a certified value obtained by other analytical methods. For the calibration of the -ray spectrometer uranium reference samples have been used which are made available jointly in Europe and the USA as Certified Reference Materials for Gamma-Ray Spectrometry (EC NRM 171 and NBS SRM 969, respectively). The measured ore has been put in a special designed container which ensured in all directions seen from the radiation window an uniform degree of infinite thickness of about 95%. The results can be taken as an example for the applicability of -ray spectrometry when high accuracy is required and under conditions were homogeneously distributed elemental uranium is embedded in larger amount of matrix material.  相似文献   

7.
In the present paper, a new improved expression for -ray detection efficiency of Ge(Li) detectors, 0 , is given. It is represented as a continuous function of x (viz. E –1) with a maximum and decreases very rapidly to a small positive value as -ray energy, E, drops to 40 keV or lower, but slowly as E rises to 1.7 MeV or higher. Since it can well represent the whole physical process of the -ray detection, this expression may be one of the simplest and most precise representations, for 0 at the present time.  相似文献   

8.
A new gamma-ray spectrum catalog and library for PGAA   总被引:1,自引:0,他引:1  
New measurements have been performed at the PGAA facility at the Budapest Research Reactor (BRR) in order to create a prompt -ray catalog for qualitative and quantitative analysis. The measured spectra were accurately analyzed by HYPERMET-PC. Prompt -ray energies and associated -ray production cross-sections have been determined by internal standardization. The resulting catalog contains prompt -ray data from neutron capture and other reactions such as (n,), and decay -ray data from short-lived reaction products. Data have been measured for nearly all stable elements, from hydrogen to uranium. Generally, data for several isotopes are given, to enable isotopic analysis as well. The whole library, including elemental spectra, will be available as a book.  相似文献   

9.
Tosylation of -cyclodextrin in an aqueous alkaline solution gave two regiospecific isomers (2-monotosyl--cyclodextrin(1) and 6-monotosyl--cyclodextrin(2)), that could recognize and catalyze small sized guest molecules; 2-monotosyl--CD recognized small sized guest molecules more effectively than did 6-monotosyl--CD.  相似文献   

10.
Zusammenfassung Es wird vorgeschlagen, die Bezeichnungen weak-field-Methode bzw. strong-field-Methode durch (L)-Methode bzw. ()-Methode zu ersetzen.Nach einer kurzen Einführung in die ()-Methode wird mit den Mitteln der Gruppen-und Darstellungstheorie eine Formel abgeleitet, mit deren Hilfe man schnell Rasse und Multiplizität der Terme eines Komplexions in der ()-Methode angeben kann. Einige Spezialfälle dieser Formel und die systematische Bestimmung der ()-Funktionen werden erörtert.
It is suggested that the misleading designations weak field method and strong field method be replaced by (L) method and () method, respectively.Following a brief introduction to the () method an equation is derived by group theoretical means which leads to rapid classification of the () terms. Several special cases and short cuts are discussed as well as the systematic determination of the () functions.

Résumé Le remplacement des termes «méthode du champ faible» et «méthode du champ fort» par «méthode (L)» et «méthode ()» est proposé.Après une introduction dans la méthode () une formule est dérivée à l'aide de la théorie des groupes et des représentations, qui donne la représentation irréductible et la multiplicité des termes d'un ion complexe dans le cadre de la méthode (). Quelques cas spéciaux de cette formule et la détermination systématique des fonctions (/gG) sont discutés.


Ich danke Herrn Professor Dr. H. Hartmann für den Hinweis auf das vorliegende Problem und der Deutsehen Forschungsgemeinschaft für ein Stipendium.  相似文献   

11.
Neutrons from a source are moderated by means of hydrogenous materials such as polyethylene (PE) or water to reduce the energy of fast neutrons and to increase the fluence rate of moderated neutrons. The rise-time and -ray pulse height spectrum from a PE moderated241Am-Be neutron-gamma (n-) mixed source were measured by using6Li-BC501 scintillation detector and pulse shape discriminator (PSD) system. The difference in rise-time between and neutron signals tumed out to be 18.5 ns for the6Li-BC501 (n-) spectrometer system. The figure of merit (FOM) for this separation was estimated to be 1.52, and this was compared with the published results. From this comparison, the6Li-BC501 system has much superior characteristics in (n-) separation to other detector systems. Two Compton edges at around 1.87 and 3.99 MeV which are produced by H(n,)D reaction and by the first excited state of12C* from Be(, n)12C* reaction were also investigated.  相似文献   

12.
The decay of 95Ru has been investigated by means of -ray spectroscopy. The 95Ru nuclei were produced by the reaction 92Mo(,n)95Ru at the beam energy of 17 MeV. High-purity Ge detectors have been used singly and in coincidence to study -rays in the decay of 95Ru to 95Tc. 132 -rays are reported, among them, energies and intensities for 127 transitions have been determined. A decay scheme of 95Ru with 31 levels is proposed which accommodates 127 of these transitions. Spins and parities for three new levels are proposed from calculated logft values, measured -ray branching ratios, and in-beam experiment results of the daughter nucleus 95Tc.  相似文献   

13.
Review of a recent paper reporting the -ray energies and intensities associated with the decay of 241Am has resulted in the conclusion that some of the rays were misidentified. The misidentified -rays are not associated with the decay of 241Am, but rather are prompt -rays from alpha-induced reactions.  相似文献   

14.
-Alumina was synthesized by thermal decomposition of aluminium(III) isopropoxide, and its properties were investigated. The change in its surface area with increasing calcination temperature resembled that of -alumina. Both aluminas had the same acid strength, and their activities in isomerization of 1-butene were the same. -Alumina as a support for molybdenum catalyst in the epoxidation of allyl alcohol also behavedin the same manner as -alumina. Thus -alumina has almost the same catalytic properties as -alumina.  相似文献   

15.
Conclusions 1. A. new route for the synthesis of optically active ,-diglycerides has been developed.2. D- and L-, -Distearins and D-, -dilinolenin have been synthesized from the readily accessible L- and D--O-tritylglycerols.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 4, pp. 210–214, 1969  相似文献   

16.
Acetylenic - and -keto alcohols and acetals of acetylenic - and -keto alcohols and acetals of acetylenic - and -formyl alcohols undergo cyclization to -dihydropyrones and -dihydrofuranones under the influence of acids.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1471–1473, November, 1976.  相似文献   

17.
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   

18.
Summary Five isomers present in technical benzene hexachloride were successfully separated by TLC on silica-gel G impregnated with silver nitrate solution. The -isomer was identified by running a control sample of -BHC. Measurement of the spot area was found suitable for the estimation of 5–20g of-BHC, and was applied to analysis of autopsy tissues. The limit of identification is 0.1g.
Zusammenfassung Auf mit Silbernitratlösung imprägniertem Kieselgel G konnten dünn-schichtchromatographisch fünf Isomere aus technischem Hexachlorbenzol erfolgreich getrennt werden. Das-Isomere wurde mit Hilfe einer Vergleichsprobe identifiziert. Die Planimetrie der Flecken eignet sich zur Schätzung von 5–20 g-Hexachlorbenzol. Die Methode wurde zur Untersuchung von Autopsieproben angewendet. Die Nachweisgrenze beträgt 0,1g.
  相似文献   

19.
Fluorescent active host labeled at the upper and lower rims of -cyclodextrin, namely, mono-3A-deoxy-3A-pyrenebutylamido-6X,Y-O-bis-pyrenebutylate-mono-altro--cyclodextrin (-3) has been synthesized as a chemosensor for steroidal guests using fluorescence spectra change upon a guest addition. The -3 shows monomer and excimer fluorescence, which results in an increase of the intensity of monomer and decrease of excimer fluorescence with a host–guest binding in the cyclodextrin cavity. The extent of monomer and excimer fluorescence variations of -3 was used as an indication for the sensing ability for the guests examined. The guest-induced fluorescence changes were measured for 10–7 M solutions of -3. The sensing parameters (Iex/I0ex and Imon/I0mono) were used to describe the sensing ability of -3. The values of Iex/I0ex describe that -3 shows less selectivity for guests than that of mono-3A-deoxy-3A-pyrenebutylamido-6X-O-mono-pyrenebutylate-mono-altro--cyclodextrin (-2), and the values of Imon/I0mono show that -3 shows higher sensitivity and selectivity than that of -2.  相似文献   

20.
A study of the precision attainable by two methods of -ray photopeak computation has been carried out. The total peak area method (TPA) and the proposed new method have been compared. The method offered is digital and simulates repeatedly accumulations of -ray spectra. The method described here computes the apparent net peak area without a clear distinction between peak and non-peak related channels. The proposed method is considered to be the most advantageous because of its relatively high precision.  相似文献   

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