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21.
Collision-induced rotational transitions in the electronically excited NaLi molecule have been studied using laser excited fluorescence. Due to the greater number of allowed transitions as compared with Na2 and Li2, more cases were found of transitions +ΔJ and ?ΔJ having greatly different cross sections (“+/ - asymmetry”). This observation is in agreement with recent predictions on the basis of Born's approximation. All observed transitions are classified according to the symmetry of the contributing potential terms. Data are presented which indicate the necessity for refinements of the theory.  相似文献   
22.
Zusammenfassung Monomere Phosphinimine der allgemeinen Formel C6H5N= =PCl n (NEt2)3-n (n=0,1,2) lassen sich (I) aus dimerem Phenylimino-phosphorsäure-trichlorid und Diäthylamin in Gegenwart eines Chlorwasserstoffakzeptors und (II) durch Reaktion der Phosphine PCl n (NEt2)3-n mit Phenylazid darstellen. Die Phosphorane Et2NPCl4, (Et2N)2PCl3 und (Et2N)3PBr2 reagieren mit Anilin nicht zu Phenylimino-Verbindungen. Durch alkalische Hydrolyse von C6H5N=PCl(NEt2)2 entsteht das Phosphorsäure-bis[diäthylamino]-anilid. Die IR- und1H- und31P-NMR-Spektren der Verbindungen werden mitgeteilt.
Monomeric phosphinimines of the general formula C6H5N= =PCl n (NEt2)3-n (n=0,1,2) are formed (I) from dimeric phenyliminophosphoricacid-trichloride and diethylamine in the presence of a HCl-acceptor and (II) by reacting the phosphines PCl n (NEt2)3-n with phenylazide. The phosphoranes Et2NPCl4, (Et2N)2PCl3 and (Et2N)3PBr2 do not give the corresponding phenylimines with aniline. Alkaline hydrolysis of C6H5N= =PCl(NEt2)2 gives bis[diethylamino]-anilido-phosphinoxid. IR-,1H- and31P-NMR-spectra are given.


Mit 1 Abbildung  相似文献   
23.
We used - coincidence spectrometry to investigate the possible presence of a meteoritical component in 27 samples of South African diamictites. Recently, several studies have suggested that some tillites/diamictites may represent impact breccias, but a petrographical study by our group found no evidence for the presence of impact-characteristic shocked minerals. The siderophile elements, such as Cr, Co, Ni, and, especially, the platinum group elements, have high abundances in meteorites, but low abundances in terrestrial crustal rocks. The Ir content of the diamictites was measured with the new iridium coincidence spectrometer (ICS) at the University of Vienna, with detection limits of around 0.02 ppb. No enrichments in the contents of Ir and other siderophile elements compared to average crustal concentrations were found; thus, no unequivocal evidence for an impact origin of these diamictites of the South African Dwyka Group can be documented.  相似文献   
24.
Historical aspects of science are usually confined to special conferences, and receive only a brief mention in the introduction to talks at meetings addressing current topics. However, at the previous Seminar, several theoretical and experimental contributions were made, which discussed the historical development of surface science. Because of the considerable interest aroused by these presentations, we decided to keep the historical spirit alive, by telling the story of photoemission.

While field emission is the oldest area of surface science, photoemission is certainly one of the most important branches. Here, emphasis is placed on the early investigations, which are often scarcely mentioned, and on more recent work that has had significant impact on the progress of surface science.  相似文献   

25.
Some generalizations of the model for odd nuclei suggested by Kerman are considered. The effects of phonon admixtures on matrix elements of Coriolis interaction are studied. Several schemes are considered for studying the role of non-adiabatic effects in the even-even core.One of the authors B. Ch. thanks L. A.Malov and V. O.Nesterenko for many discussions of some questions connected with the determination of the phonon-quasiparticle admixtures.  相似文献   
26.
Zusammenfassung Es wurde festgestellt, daß die Farbe einer Actinomycin C-Lösung in sehr engem Zusammenhang mit der Konzentration dieser Substanz in der Lösung steht. Die photometrisch ermittelte Farbabnahme geht mit dem durch mikrobiologischen Test bestimmten Aktivitätsverlust in vieler Hinsicht parallel. Bei der Aktivitätsabnahme spielt die Art des Lösungsmittels eine wichtige Rolle. Die stärkste Aktivitätsminderung nach dem Erhitzen wurde in bidest. Wasser, die geringste Aktivitätsabnahme in Glykokollpuffer beobachtet.
Summary The concentration of active actinomycin C in a solution can be determined quite simply by a photometric method. Comparison of results showed good agreement between the microbiological tests and the photometric method. Actinomycin C suffers most loss of activity by heating when dissolved in distilled water and least when dissolved in glycine buffer.
  相似文献   
27.
In the actinides bothi 13/2 protons andj 15/2 neutrons are close to the Fermi surface. At rapid rotation these high-j particles will unpair and align their orbital angular momentum along the axis of rotation giving rise tos-bands that cross the ground-state band. Coulomb excitation of the odd nuclei 237 93 Np (established up to the 45/2+ state) and 235 92 U (established up to the 51/2? state) provides specific information about these band crossings: From the saturating alignment of the odd high-j particle in both nuclei at intermediate rotational frequencies we find the aligned angular momentum of thei 13/2 protons-band to be 6.6? while the corresponding value for thej 15/2 neutrons-band is 5.5?. At more rapid rotation above ?ω=0.18 MeV we observe additional alignment in235U. This is ascribed to the interaction of the protons-band. From the gradual onset of the additional alignment we deduce that forZ=92 the protons-band interacts strongly with the ground-state band and from a comparison of the actual amount of alignment with the full value of 6.6? we estimate the crossing to occur around ?gw c p =0.25 MeV.  相似文献   
28.
The membrane destabilizing and fusogenic properties of the synthetic peptide VP3(110-121), corresponding to an immunogenic sequence of the hepatitis A virus (HAV) VP3 capsid protein, were studied. By tryptophan fluorescence and acryalmide quenching it was demonstrated that the peptide binds liposomes of POPC-SM-DPPE (47 + 39 + 14) and POPC-SM-DPPE-DOTAP (40 + 33 + 12 + 15) and penetrates the membrane, at both neutral and acidic pH (POPC = 1-palmitoyl-2-oleoylglycero-sn-3-phosphocholine; SM = sphingomyelin; DPPE = 1,2-dipalmitoylphosphatidylethanolamine; DOTAP = 1,2-dioleoyl-3-trimethylammoniumpropane). VP3(110-121) did not have membrane-destabilizing properties at neutral pH. Acid-induced destabilization of the vesicles was demonstrated by fluorescence techniques and dynamic light scattering. VP3(110-121) induced aggregation of POPC-SM-DPPE-DOTAP (40 + 33 + 12 + 15) vesicles, lipid mixing and leakage of vesicle contents, all consistent with fusion of vesicles. In POPC-SM-DPPE (47 + 39 + 14) vesicles, at acidic pH, VP3(110-121) induced membrane destabilization with leakage of contents but without aggregation of vesicles or lipid mixing. The peptide only showed fusogenic properties when bound to the vesicles at neutral pH before acidification to pH below 6.0, and no effect was seen if the peptide was added to vesicles already set at acidic pH. These results may have physiological significance in the mechanism of infection of host hepatic cells by HAV.  相似文献   
29.
The alkyl (aryl)-bishydroxymethylphosphines react with primary amines to give the title compounds. With optically active amines optically active phosphines are formed.  相似文献   
30.
Zusammenfassung Eine Methode zur potentiometrischen Titration von Sulfid mit Natriumplumbat(II)lösung an einer sulfidsensitiven Membranelektrode wird beschrieben. Sie eignet sich zur Bestimmung von 10–4% Sulfid in Gegenwart von Cl, Br, J, SCN, SO3 2–, S2O3 2–
Titration of sulphide with a sulphide-ion sensitive electrode
A method is described for the titration of sulphide with sodium plumbate(II) solution using a sulphide-sensitive electrode. The method is suitable for the determination of 10–4% of sulphide in the presence of Cl, Br, J, SCN, SO3 2–, S2O3 2–.


Wir danken Herrn Dr. K. Obst für wertvolle Hinweise und Diskussionen.  相似文献   
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