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A time‐of‐flight apparatus is described for measuring the inelastic energy loss incurred by fast (< 50–350 eV) alkali atoms in ionizing collisions with diatomic molecules. The inelastic energy losses were found to be nearly energy independent for collisions between K and Cs with Cl2, Br2, and O2, and it is furthermore shown that these energy losses are from about 8 to 10 eV, irrespective of the reactants. The collisions between alkali atoms and halogen molecules (Cl2 and Br2) yield as intermediate alkali ions (M+) and excited molecular ions, (X2−) in the 2Σg state, followed by dissociation to the ground‐state halogen ions and excited halogen atoms. In the case of oxygen, excited molecular ions in the 2πu state are formed and these species either remain in the bound state of the 2πu or decay to vibrationally excited molecular states (bΣg+, aΔg). The excitation functions (change of cross sections with incident energy variations) are interpreted in terms of curve crossings near or inside the equilibrium dist...

Im Jahre 1971 wurden 30 thalidomidgeschadigte Dysmeliekinder mit einem Durchschnittsalter von 10 Jahren und 1 Monat zahnarztlich untersucht. Anhand der erstellten Unterlagen ergab sich: 1. Sowohl die anamnestischen Angaben wie die klinische Untersuchung der Mundhohle und die Auswertung der Rontgenaufnahmen ergaben keine auffalligen Besonderheiten. 2. Die Verteilung und Haufigkeit der Kieferanomalien war ebenfalls normal und wies keine Besonderheiten auf. Lediglich mandibulare Verlagerungen (besonders nach rechts) wurden gehauft angetroffen. 3. Die Auswertung des Profil-Fotostatbildes ergab gehauft

The enrichment of tRNA at specific sites with carbon-13 has been accomplished in vivo using a mutant of Escherichia coli. A relaxed strain of E. coli auxotrophic for methionine was grown in a specifically defined medium supplemented with either [14C] or [13C]-methyl labeled methionine. Cells were collected at the end of the log-phase of growth and tRNA was extracted. Analysis of the radioactivity of the [14C]-labeled tRNA established an incorporation ratio of three labeled carbons per tRNA molecule. Incorporation of the [14C]-label in vivo was confined to the methylation of nucleotides as determined by thin layer chromatography of nucleotides resulting from a ribonuclease digestion of [14C]-labeled tRNA. The carbon-13 NMR spectrum of [13C]-enriched tRNA indicated a similar degree of incorporation into the methylated nucleotides by the substantial enhancement of [13C]-methyl NMR signals only. Assignment of signals has been made for the methyl groups of ribothymidine and N7-methylguanosine in E. coli tRNA.

Iron clusters have been prepared within zeolite holes by reduction of zeolites containing ferrous ions. The diameter of these particles must therefore be smaller than 13 Å. They are super-paramagnetic and their Mössbauer spectra show no HFS, even at 4 K. The temperature dependence of the magnetic susceptibility of the unreduced zeolites obeys a Curie-Weiss law with peff = 4,54 μB and Θ = 105 K. The Weiss curves of the reduced samples lie distinctly below those of the bulk material.

The density of crystals of poly(ethylene terephthalate), (PETP), Qc is checked by X-ray diffraction assuming a triclinic unit cell and the indices of reflections as found by Bunn. The following unit cell dimensions are found: a = 4,48A, b = 5,85A, c = 10,75 A, α = 99,5°, β = 118,4°, and γ = 111,2°. This gives the density Qc as 1,515g/cm3 which is about 4% higher than that reported by Bunn. Negligible differences in spacings for samples annealed at different temperatures (120°C–260°C) have been found. Only for an annealing temperature of 100°C the higher d-values lead to Qc = 1,484g/cm3. For undrawn PETP films annealed at 250°C the same value of Qc as for drawn PETP was obtained on the basis of Guinier X-ray patterns. No systematic variation of crystal plane spacings was found for drawn PETP fibers annealed at 220°C and containing mole fractions of 1,7 to 4,2% diethylene glycol, (2,2′-oxydiethanol), as comonomer.

The ortho-para conversion in solid hydrogen is investigated at 12, 4.2, and 1.57 K in long-term experiments up to 1200 h. The results are discussed in the light of the influence of molecular diffusion on the conversion rate. At 4.2 and 1.57 K, the conversion rate shows that the diffusion coefficient is $D\ensuremath{\approx}{10}^{\ensuremath{-}20}$ ${\mathrm{cm}}^{2}$ ${\mathrm{sec}}^{\ensuremath{-}1}$. This value is much larger than those predicted from an extrapolation of experimental results at higher temperatures and from recent theoretical predictions. At 1.57 K, an increase of the conversion rate with decreasing $o\ensuremath{-}{\mathrm{H}}_{2}$ concentration is observed. Calculations show this increase is due to clustering of $o\ensuremath{-}{\mathrm{H}}_{2}$ molecules caused by electric quadrupole-quadrupole interactions between them. The estimated diffusion rate is consistent with that found previously from the rate of clustering.

Diffusion from a metallic gold source into SiO2 films on (100) silicon substrates at 1000 °C for 15 min leads to large negative shifts in the C‐V curves and distortion of the C‐V characteristics. Annealing in hydrogen in the temperature range 300–450 °C, in argon at 1100 °C, or short exposure to steam at 950 °C is only partially effective in reversing these changes. Gold from a metallic source appears to diffuse in SiO2 mostly or exclusively as metallic gold and to cause the generation of a very large density of interface states. Most of the negative C‐V shift is due to these interface states and not due to a laterally uniform fixed oxide charge, as claimed by other researchers. The magnitude of the effect depends in the thickness of the gold film, and hence directly or indirectly on the amount of gold diffused into the SiO2 film because thicker gold films result in larger amounts of gold diffusion in uniform fashion into the SiO2. The total amount of gold in the SiO2 film after diffusion, however, is ins...

The rate constant for attachment of electrons to SF 6 was measured as a function of the electric field strength in liquid argon and xenon. At higher field strengths a decrease in the rate of attachment occurs which is interpreted by means of the hot electron theory of Cohen and Lekner.

Solutions to old problems are sometimes found in new paradigms and models which provide alternative means of approach and analysis. It is suggested here that South Africa's socio-economic and political problems, stemming from the country's multi-ethnic structure, may be viewed within a conceptual framework that emphasises the spatial dimensions of the associated conflict. A model suitable for understanding this will stress the many disparities and tensions between the white core élites and those black counter-élites – including the leaders in the Homelands – who are emerging from the subdominant peripheral groups. Moreover, an analysis of the interaction between core and periphery will highlight the transformation necessary to reduce and resolve the conflict between whites and blacks in the South African spatial system and so promote their more equitable development?

Die durch Feldemission (FE) in flussigem α-Methylstyrol ausgeloste Polymerisation wird durch Kationenfanger (N(C2H5)3, H2O, Cyclopropan) inhibiert. Die Elektronenfanger SF6, N2O, CO2 und O2 inhibieren ebenfalls, wobei die Inhibitorwirksamkeit in der genannten Reihenfolge abnimmt. Dieses Verhalten wird darauf zuruckgefuhrt, das von der Hochfeldelektrode emittierte Elektronen Monomermolekeln ionisieren; dabei gebildete Radikalkationen starten die kationische Polymerisation. Durch Kationenfanger wird daher die Wachstumsreaktion inhibiert, wahrend Elektronenfanger die Startreaktion inhibieren. Bei der durch Feldionisation (FI) gestarteten Polymerisation sind Elektronenfanger wirkungslos; Kationenfanger inhibieren dagegen. Aufgrund der Abhangigkeit der spezifischen Polymerausbeute von der N(C2H5)3-Konzentration wurde abgeschatzt, das im Falle der FE nur 1 bis 10% der emittierten Elektronen polymerisationsauslosend wirken. Im Falle der FI starten bis zu 100% der an der Hochfeldelektrode erzeugten Ladungstrager kinetische Ketten. Bei allen Versuchen wurde Oligomeres (Polymerisationsgrad 3 bis 4) durch eine Kettenreaktion gebildet. Die spezifische Oligomerausbeute nahm bei der FE-initiierten Polymerisation mit steigender SF6-Konzentration bemerkenswert zu. Cation scavengers (N(C2H5)3, H2O, cyclopropane) inhibit the polymerization of liquid α-methylstyrene initiated by field emission (FE). Electron scavengers also inhibit the polymerization with efficiencies declining in the series SF6>N2O>CO2>O2. It is assumed that electrons emitted by the high field electrode ionize monomer molecules. Radical cations formed thereby initiate the cationic polymerization. Thus cation scavengers inhibit the growth of kinetic chains, whereas electron scavengers inhibit the initiation reaction. The polymerization initiated by field ionization (FI) is not affected by electron scavengers. However, cation scavengers inhibit this polymerization. Based on the dependence of the specific polymer yield on the N(C2H5)3-concentration it was estimated that in the case of FE only 1 to 10% of the emitted electrons initiate polymerization. In the case of FI up to 100% of the ions generated at the high field electrode start kinetic chains. During all experiments oligomer (degree of polymerization 3 to 4) was formed in a chain reaction. The specific oligomer yield increased with increasing SF6-concentration significantly when the reaction was initiated by FE.

The mobility of excess electrons in liquid mixtures of methane and ethane was measured over the entire range of composition at T=111 °K. Field dependent mobilities were observed at higher field strengths. The data are discussed on the basis of the quasifree and localized electron models.

The rates of electron attachment to SF/sub 6/ were measured in liquid methane, ethane, and propane as a function of the temperature. The data are discussed with relation to the models proposed for the electron motion in these liquids. (auth)

Ma Huang, identified as Ephedra vulgaris var. helvetica, has been known to Chinese medicine since about 3100 B. C., when it was one of the herbs tested and approved by Emperor Shen Nung. According ...

In this paper an apparatus is developed which is capable of measuring the thermal conductivity of gases, vapors, and liquids over a wide range of temperatures. A compensating-type hot-wire apparatus was employed to make absolute thermal-conductivity determinations of various fluids; in particular, air was used to check the agreement of experimental results between previous investigations and the present one. In addition, the thermal conductivities of furfural vapor and liquid were measured in order to supplement existing data in the field of heat conduction with results of considerable industrial importance.

Die im Rontgenkleinwinkeldiagramm von verstrecktem Polyathylen auftretenden Meridian- Interferenzen werden durch eine nahezu periodische Anordnung von kristallinen und fehlgeordneten Bereichen hervorgerufen. Die durch den mittleren Abstand zweier aufeinanderfolgender Kristallite definierte Langperiode hangt von der Vorbehandlung ab. Zeit- und Temperaturabhangigkeit der Lage der Kleinwinkelreflexe wurde untersucht. Die beim Tempern stattfindende Umkristallisation, die zu einem Anwachsen der Langperiode fuhrt, wurde auch mit anderen Mesmethoden verfolgt. Vergleichende Untersuchungen wurden an unverstrecktem, massivem Polyathylen und an Polyathylen-Einkristallen durchgefuhrt. Die Langperiode wachst in diesen Fallen nach dem gleichen Zeitgesetz wie bei verstreckten Folien. Bezuglich des Zusammenhanges zwischen Dichte und Langperiode ergaben sich jedoch charakteristische Unterschiede. Sie werden darauf zuruckgefuhrt, das die Ketten bei den Einkristallen und im schmelzkristallisierten Material an den Grenzflachen der Kristallite gefaltet sind, im verstreckten Polyathylen dagegen nicht. Auf den Zusammenhang des Langperiodenwachstums mit anderen im gleichen Temperaturbereich beobachteten Vorgangen (partielles Schmelzen, Nachkristallisation wird hingewiesen).

N,N′,N′′-Trihydroxymethyl-melamin (I) zeigt am Yoshida-Sarkom und am Sarkom 180 eine ausgepragte Wirkung, wahrend analoge N-CH2X-Verbindungen (X = OCH3, SO3Na, CN, SC2H5, Morpholin) eine geringe oder keine Wirkung aufwiesen. I ist im Gegensatz zu seinen Analogen zur Aminomethylierung nukleophiler Substrate unter physiologischen Bedingungen fahig, wie am Beispiel der Umsetzung von I mit Morpholin gezeigt wurde. The Carcinostatic Effect of N,N′,N′′-Trihydroxymethyl-melamine and Analogous Compounds N,N′,N′-Trihydroxymethyl-melamine (I) shows a marked effect on the Yoshida Sarcoma and the sarcoma 180, while analogous N-CH2X compounds (X = OCH3, SO3Na, CN, SC2 H5, morpholine) exhibit a poor or no effect. In contrast to its analogs I is capable of aminomethylating nucleophilic substrates under physiological conditions as shown by the reaction of I with morpholine.

In dieser Ubersicht wurden die folgenden aktuellen Probleme der Sinnesphysiologie und -psychologie behandelt: 1. An Hand von Beispielen aus unserem Laboratorium wurde gezeigt, das die Hautreceptoren eine selektive (spezifische) Empfindlichkeit besitzen und das den verschieden funktionell definierbaren Receptoren definierte histologische Strukturen entsprechen. 2. Eine auf neurophysiologischen und psychophysischen Ergebnissen basierende erweiterte Einteilung der drei „klassischen“ Hautsinne, Tast-, Temperatur- und Schmerzsinn, wird vorgeschlagen. 3. Es wird diskutiert, welche zentralnervosen Prozesse fur den psychophysisch gefundenen Zusammenhang zwischen Reizintensitat und subjektiver Empfindung verantwortlich sind. 4. Abschatzungen der Kanalkapazitat fur die Ubertragung der Intensitatsinformationen bei mechanischen Hautreizen wurden fur einzelne Receptoren und fur Receptorpopulationen durchgefuhrt. Diese Kapazitat ist bei Receptoren mit myelinisierten Afferenzen wesentlich groser als bei solchen mit unmyelinisierten Afferenzen. Die Informationskapazitat der Hautsinne wird schlieslich kurz mit den anderen Sinnesorganen verglichen.

Carbon additions increase the strength of tantalum as do oxygen and nitrogen additions. However, the effectiveness of carbon as a strengthener does not diminish as rapidly with increasing temperature up to at least 2,700°F as does the effectiveness of oxygen or nitrogen. This is because carbon reacts with tantalum to form finely dispersed carbides even in the absence of zirconium. Carbide dispersions can be used as an auxiliary strengthener of solid-solution-strengthened tantalum-base alloys. At very high temperatures (above about 3,000°F) the carbon solubility in tantalum increases rapidly with temperature, and even the reactive metal carbides dissolve in tantalum. and lose their effectiveness.

1. In cats anaesthetized with Nembutal, the cutaneous receptive fields of individual cerebellar climbing fibres were assessed by recording the climbing fibre responses of single Purkyně cells following controlled mechanical stimulation (air jets, vibration, taps, pressure) of the foot pads of all four limbs and of the hairy skin of the limbs and the body. 2. Three major types of cutaneous receptive fields of individual climbing fibres were recognized: (a) restricted fields generally confined to the distal areas of one limb only; (b) circumscribed fields on the distal areas of two to four limbs (discontinuous fields); and (c) widespread continuous fields extending over all or almost all of the body surface. A fourth group appears to receive cutaneous inputs from one limb and sensory input from deeper structures in other limbs. 3. Thresholds for tapping of the foot pads were often quite low (< 100 μm indentation), and there was no noticeable difference in the distribution of thresholds between the climbing fibres having restricted or more widespread cutaneous receptive fields. Similarly, the latencies of climbing fibre responses evoked by vibration and tapping were in the same ranges for climbing fibres with receptive fields restricted to one limb only and for those having more widespread fields. 4. In regard to location in the anterior lobe of the cerebellum it was found that those climbing fibres receiving inputs only from the ipsilateral forelimb projected to Purkyně cells located almost entirely in lobule V, whereas all other climbing fibres with restricted or more widespread receptive fields projected to Purkyně cells distributed widely within lobules II to V.

Zusammenfassung Bisher wurden Coli der 0-Gruppe 26 nur wenig und meist bei sporadischen Fallen von Sauglingsenteritis gefunden. In der vorliegenden Arbeit wird auf die auffallige Zunahme dieser Colitypen in unserem Krankengut hingewiesen und die Beschreibung von insgesamt 158 Fallen gegeben. Die Beobachtung einer Kleinraumepidemie und die nicht kleine Zahl erst in der Klinik stattgefundener Ubertragungen geben uns Anlass, die Bedeutung auch dieser Dyspepsiecoli fur den Hospitalismus nicht zu gering zu veranschlagen. The Prevalence of Bact. Coli 0 26 in Infantile Diarrhoea. In the Pediatric Clinic of Rostock, East-Germany, B. Coli 0 26 were occasionally found in cases of infantile diarrhoea. These Coli types have now become very frequent and have been observed in 158 cases. An epidemic within a small-room ward was studied, some cases becoming infected while in the hospital. The importance of these dyspepsia Coli for cross-infections in hospital wards should not be underestimated. La frequence du Bact. Coli 0 26 dans la diarrhee du nourrisson. A la clinique pediatrique de Rostock, Allemagne Orientale, le Coli 0 26 n'a ete trouve que rarement et dans des cas sporadiques de diarrhee infantile. Ces types de Coli sont maintenant devenus tres frequents et on les a rencontres dans 158 cas. On a examine une epidemie dans deux petites salles et assez bien de cas devinrent infectes pendant l'hospitalisation. On ne peut sousestimer l'importance de ces Coli de dyspepsie pour le developpement de l'hypothrepsie hospitaliere. El bacilo Coli 0 26 en diarrea infantil. En la Clinica Pediatrica de Rostock, Alemania del Este, se encontro el Bacilo Coli 0 26 solamente en raros y esporadicos casos de diarrea infantil. Este tipo de Coli se ha vuelto actualmente muy frecuente y fue observado en 158 casos. Se estudio una epidemia en dos pequenas salas y se encontro que varios casos en el hospital se infectaron durante ese periodo. No deberia subestimarse la importancia de esas dispepsias a Bac. Coli en el desenvolvimiento de hospitalismos.

After “cooling”, the hot tritium atoms formed above thermal energies by nuclear reactions abstract or replace hydrogen atoms, and replace substituents X (e.g. alkyl, NH2, NO2, OH, COOH, F, Cl, Br, or I) in organic compounds. Isotope effects have been observed for protonated vs. deuterated compounds in several hot reactions. Models and mechanisms are discussed for the abstraction and replacement, for specific reactions on certain carbon atoms, and for the isotope effects. These are based on steric, bond-energy, and kinetic considerations.

Nozzle boundary layer and heat transfer measurements are presented for nozzles having half angles of convergence of 30 and 60 deg, each operating in conjunction with a short and long uncooled pipe inlet. The long inlet, which produced a fully developed turbulent boundary layer at the nozzle entrance, did not significantly alter the nozzle heat transfer distribution relative to values obtained with the short pipe inlet. Peak heat transfer coefficients for the high convergence nozzle were nearly 40 percent higher than the peak value for the 30 deg half angle of convergence nozzle. Measured heat transfer coefficients were compared to predictions based on a boundary layer theory and a pipe flow type correlation.

Aus Kernreaktionen stammende „heise” Tritiumatome mit mehr als thermischer Energie abstrahieren oder substituieren nach einer gewissen „Abkuhlung” in organischen Verbindungen (RH, RX) Wasserstoff oder Substituenten × (z. B. CH3, NH2, NO2, OH, COOH, F, Cl, Br, J). Bei allen Reaktionen mit Tritium beobachtet man zwischen protonierten und deuterierten Verbindungen Isotopie-Effekte. Fur die Alternative Substitution oder Abstraktion, fur die spezifische Reaktion an bestimmten C-Atomen und fur die Isotopie-Effekte werden Modelle und Mechanismen diskutiert. Diesen liegen sterische, bindungsenergetische und kinetische Annahmen zugrunde.