bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of chosen factors in the wide crossing
method for the production of oat doubled haploids
Authors: Nowakowska Agata , Skrzypek Edyta , Marcińska Izabela , Czyczyło-Mysza Ilona , Dziurka Kinga , Juzoń Katarzyna , Cyganek Katarzyna , Warchoł Marzena 
Published: February 2015

Abstract
Oat (Avena sativa L.) has recently gained
importance due to the discovery of a variety of health
benefits and new opportunities of use. There is no efficient
protocol for the production of oat doubled haploid (DH)
lines. The aim of this study was to increase the efficiency
of obtaining DHs of oat by the wide crossing method.
The study was performed on five oat genotypes. We have
compared the induction of embryos after pollination
with maize, sorghum and millet pollen as well as the
development of haploid embryos isolated 2, 3 and 4 weeks
after pollination and cultivated on media with different
sugar content. Haploid plants were treated with colchicine
after or before acclimation to natural conditions. Of the
three types of pollen used, the largest number of haploid
embryos was obtained using maize pollen. Three weeks
after pollination was the most suitable time for the
isolation and cultivation of the embryos. The most efficient
medium enabling the development of embryos and
conversion to plants was 190-2 containing 9% of maltose.
Colchicine treatment of acclimated plants provided high
survival rate.
Quantile Regression with Clustered Data
Authors: Parente Paulo M.D.C. , Santos Silva João M.C. 
Published: February 2015

AbstractWe study the properties of the quantile regression estimator when data are sampled from independent and identically distributed clusters, and show that the estimator is consistent and asymptotically normal even when there is intra-cluster correlation. A consistent estimator of the covariance matrix of the asymptotic distribution is provided, and we propose a specification test capable of detecting the presence of intra-cluster correlation. A small simulation study illustrates the finite sample performance of the test and of the covariance matrix estimator.
On the number of maximal subgroups in a finite group
Authors: Lauderdale L.-K. 
Published: February 2015

Abstract
For a finite group G, let m(G) denote the set of maximal subgroups of G and
π(G) denote the set of primes which divide |G|. In [Arch. Math. 101 (2013), 9–15], it is proven that |m(G)| = |π(G)| when G is cyclic and if G is noncyclic |m(G)| ≥ |π(G)| + p, where
p ∈ π(G) is the smallest prime that divides |G|. In this paper, we produce two new lower bounds for |m(G)|, both of which consider all of the primes in π(G).
Linear and projective boundaries in HNN-extensions and distortion phenomena
Authors: Krön Bernhard , Lehnert Jörg , Stein Maya 
Published: February 2015

Abstract
Linear and projective boundaries of Cayley graphs were introduced in [Glasg. Math. J. (2014), DOI 10.1017/S0017089514000512] as quasi-isometry invariant boundaries of finitely generated groups. They consist of forward orbits g
∞ = {gi
: i ∈ ℕ}, or orbits g
±∞ = {gi
: i ∈ ℤ}, respectively, of non-torsion elements g of the group G, where `sufficiently close' (forward) orbits become identified, together with a metric bounded by 1.

We show that for all finitely generated groups, the distance between the antipodal points g
∞ and g
-∞ in the linear boundary is bounded from below by 1/21/2, and we give an example of a group which has two antipodal elements of distance at most (12/17)1/2 < 1. Our example is a derivation of the Baumslag–Gersten group.

We also exhibit a group with elements g and h such that g
∞ = h
∞, but g
-∞ ≠ h
-∞. Furthermore, we introduce a notion of average-case-distortion—called growth—and compute explicit positive lower bounds for distances between points g
∞ and h
∞ which are limits of group elements g and h with different growth.
Messungen der druckabhängigen Relaxationszeiten der Ausrichtung (alignment) einiger durch Ionenstoß angeregter Helium-Singulettzustände
Authors: Drtil W. 
Published: February 2015

Abstract
Zur Bestimmung der Druckabhängigkeit der Relaxationszeiten der Ausrichtung (alignment) der He 3 1P-, 4 1P-, 3 1D-, 4 1D-und 5 1D-Zustände in Abhängigkeit vom Heliumdruck wurden Hanle-Effekt-Messungen bei Ionenstoßanregung durchgeführt. Durch Extrapolation ergaben sich die natürlichen Lebensdauern der untersuchten Zustände zu τ(3 1P) = (2,0 ± 0,8) ns (1,7 ns); τ(4 1P) = (4,0 ±0,6) ns (3,9 ns), τ(3 1D) = (20,5 ±0,9 ns) (15,4 ns), τ(4 1D) = (38,0 ±2) ns (37,8 ns), τ(5 1D) = (68 ±7) ns (72,7 ns). Außerdem konnten aus der Druckabhängigkeit der Relaxationszeiten der 3 1D-, 4 1D-und 5 1D-Zustände die Wirkungsquerschnitte der Zerstörung der Ausrichtung (alignment) durch Stöße mit Atomen im angeregten Zustand und Atomen im Grundzustand ermittelt werden:
σ(2) (3 1D) = 6 · 1 0-14 cm2, σ(2) (4 1D) =4·10-14 cm2, σ(2) (5 1D) = 7·10-14 cm2 (T = 297 °K).
Notizen:β-Modifikation des Bariums bei im Vakuum zerstäubten Partikeln
Authors: Batalli-Cosmovici Cristiano 
Published: February 2015

Abstract
Das bei Normaldruck und unter 375 °C stabile a-Barium besitzt ein kubisch-raumzentriertes Gitter. Zwischen 350° und 380 °C erfolgt eine allotrope Um­ wandlung zum /^-Barium von bislang unbekannter Struktur 1. Kleine Partikel mit Radius unter 5)jl lassen sich ent­ weder durch Strahlungskühlung oder Wärmeleitung rasch abschrecken, so daß die metastabile Modifikation einfriert, oder bei der Analyse durch einen Elektronen­ strahl bis in den Stabilitätsbereich dieser Modifikation erhitzen. Dies wird mit dem folgenden Ergebnis illu­ striert, das an metallischen Partikeln aus einer Zwei-phasen-Strömung ins Vakuum gewonnen wurde. Gepreßte Ba-CuO-Mischungen (in molarem Mischungs­ verhältnis 2,5:1) wurden in Verbrennungsgefäßen von 50 cm3 gezündet, die mit einer Wolframdüse versehen waren. Die Reaktionsprodukte (Tröpfchen von Ba, BaO, Cu und gasförmiges Ba mit N2 bei 2500 °K) strömten innerhalb von 300 msec in eine Vakuumkam­ mer von 20 m3 bei einem Anfangsdruck von 10-5 Torr. Die Teilchen dieser Zweiphasen-Strömung wurden mit einem besonderen Auffanggerät 2 in einem Abstand von 330 cm von der Düse gesammelt. Um Oxidation der Teilchen zu vermeiden, wurde das Auffanggerät nach dem Experiment mit Argon auf einen Druck P
Quasi-Darkén sche Beziehungen
Authors: Klemm A. 
Published: February 2015

Abstract
Quasi-Darkén Relations. In binary mixtures with the self­friction coefficients r11 and r22 and the inter-friction coefficient r12, interpolations of the type 2 f (r12) = f (r11) + f (r22) cor­respound to Quasi-Darkén relations, If f = In, the Darkén relation is obtained.
A Liquid Crystal as a Solvent in Infrared Spectroscopy
Authors: Hansen Torben Stroyer 
Published: February 2015

Abstract
A technique to obtain infrared absorption spectra of orientated molecules, dissolved in a liquid crystal, which is placed in a strong magnetic field, is described. The degree of orienta­tion of 4,4'-dihexoxyazoxybenzene is measured at various temperatures. The maximum degree of orientation of 4-bromo-benzonitrile and 4-cyanobenzoic acid is measured in a 10% solution in 4,4'-dihexoxyazoxybenzene to be 0.35 and 0.55, respectively.
Anomalie der g-Faktoren symmetrisch phenylsubstituierter aromatischer Radikale
Authors: Möbius K. , Plato M. 
Published: February 2015

Abstract
For the phenylsubstituted hydrocarbon radicals of p-terphenyl, diphenylanthracene, rubrene, tetraphenylpyrene, and triphenylmethyl we have observed g-factors showing pronounced deviations from the values expected by Stone's g-factor theory. In some cases the deviations are as large as -1.6X10 -4 which cannot be explained in the frame of the conventional HMO conjugation model. A new model with additional consideration of a hyperconjugative coupling between the π-orbitals and the σ-orbitals of the twisted phenyl rings is presented which, in connection with certatin modifications of Stone's theory, explains the observed g-factor anomaly. Details of the hyperconjugative model of twisted phenyl rings are presented in a subsequent paper.
Energiebestimmung der Stoßwelle eines laserinduzierten Gasdurchbruchs
Authors: Hohla K , Büchl K , Wienecke R , Witkowski S 
Published: February 2015

Abstract
A gas breakdown was produced in the gases H2, N2 , He, Ar and Xe with a 100 MW ruby laser in a pressure chamber, the gas pressure being varied from 200 Torr to 10 atm. A lense with a focal length of 16 mm was used for focusing the laser beam. The blastwave was observed using the shadow method. High-speed pictures and streak pictures of the blastwave were taken with an image converter camera. The shape of the blastwave was approximately spherical. The position of the shock-front was determined as a function of time by streak pictures and compared with Sakurai's theory for H2 and N2 for Mach numbers M ≧ 2 and for Xe, Ar and He for M ≧ 4. From the normalization parameter it is possible to determine the energy of the blastwave for various gases as a function of the pressure of the gases. In the gases He and H2 pronounced rise of the blastwave energy was found with rising pressure. However, in the gases N2 , Xe and Ar there exists a maximum in the blastwave energy at a pressure of approximately 1 atm. A preliminary explanation for this behaviour is given.
Der aus dem Noetherschen Theorem folgende Energie-Impulstensor für das elektromagnetische Feld in Materie
Authors: Schröder U.E. 
Published: February 2015

Abstract
The often discussed question concerning the energy-momentum tensor of the electromagnetic field in matter can be answered using NOETHER'S theorem. The separation of the electromagnetic system from the mechanical system introduced here leads to the asymmetric expression for the energy momentum tensor. From covariance with respect to scale transformations one further concludes that the trace of the energy-momentum tensor vanishes.
Microwave Spectrum, Structure and Rotation-Vibration Interaction of Deutero-Fulminic Acid, DCNO
Authors: Bodenseh Hans Karl , Winnewisser Manfred 
Published: February 2015

The microwave spectrum of the deuterated form of fulminic acid (DCNO) has been investigated in the frequency region from 9 to 42 GHz. For the ground vibrational state of DCNO the following rotational constants were obtained:
B0(D12C14N16O) =10 292.50 MHz,
B0(D13C14N18O) =10 011.66 MHz,
B0(D12C14N18O) = 9 758.87 MHz.
The corresponding moments of inertia yield a combined rs and r0 structure:
rDC = 1.027 ±0.001 Å, rCN = 1·168 ±0.001 Å, rNO = 1.199 ± 0.001 Å.
For the two degenerate bending modes ν4 and ν5 the l-type doublets of the transition J = 1 - 2 and the two corresponding series of l-type doubling transitions have been observed. The analysis of the two l-type doubling series revealed that P4 and P6 centrifugal distortion contributions are sufficient to account for the spectrum. The doubling constants given in MHz are
q4 = 17.9103-(0.6467 · 10-4)J(J + 1) +(0.188 · 10-8) [J(J + 1)]2,
q5 = 38.0907-(0.3061 · 10-3)J(J + 1) + (0.314 · 10-8)[J(J + 1) ]2.
A third series of l-type doubling transitions arising from the II-level of the ν5=3 vibrational state has been found and analysed, yielding:
q(0)
3×5 =29.2748 ± 1.8 · 10-4 MHz; EΦ-EII=Δ ≅ 41 cm-1.
Mikrowellenspektrum, Hinderungspotential der internen Rotation, Quadrupolkopplungskonstanten und Dipolmoment des 2-Methyl-Pyridins
Authors: Dreizler H. , Rudolph H.D. , Mäder H. 
Published: February 2015

Abstract
The microwave rotational spectrum of 2-methyl-pyridine (a-picoline) has been investigated in the region from 6 to 30 kmc/s. From the three lowest states of internal rotation m=0, 1, 2 the three-and sixfold components V3 and V6 of the potential barrier hindering the internal rotation have been determined to be V3= (258,4 ± 0,1) cal/mole and V6=(-11,8± 0,1) cal/mole. From the splitting of low-J lines m=0 the nuclear quadrupole coupling constants for the 14N nucleus have been derived as χaa= (-0,33 ± 0,02) mc/s, χbb = (-2,86 ± 0,02) mc/s, χcc = (+3,19 ± 0,02) mc/s. The hyperfine structure of rotational transitions in excited states of internal rotation could also be accounted for with these coupling constants. The dipole moment components derived from Stark-effect measurements in the ground torsional state m = 0 are μa = (0,72 ± 0,01) Debye and μb - (1,71 ± 0,02) Debye.
Molten Mixtures of K, Na Formates with Alkali Halides. Note I
Authors: Leonesi Dante , Braghetti Mario , Cingolani Augusto , Franzosini Paolo 
Published: February 2015

Abstract
The eutectic compositions and temperatures were determined in a series of mixtures type HCOOK+MeX and HCOONa+MeX (where Me=Li, Na, K, Rb, Cs, and X=Cl, Br, I). Moreover, a detailed map of the accessible portion of the liquidus area in the system K+, Na+/HCOO-, Cl-, showing the isotherms up to 300 °C, was drawn.
Through a Layer of Lorentzian Absorbers. Part II
Authors: Franco Sergio , Heberle Juergen 
Published: February 2015

Abstract
The formalism presented in Part I has been developed further. By analytical methods we have derived a formula for the linewidth
W= (⌈S + ⌈A) {1+γT[1+γT/2!-(γ+1)2 T2/3!- (7 γ3 + 6γ2-2) T3/4! + ⅓\ (31 γ4+ 120 γ3+156 γ2+72 γ+6) T4/5! +…] }
where γ = ⌈A/⌈S and T is a new dimensionless parameter which is proportional to the absorber thickness. The application to Mössbauer spectroscopy is discussed. The results are valid for environmental broadening of the Lorentzian type.
Experimental Investigation of a Low Frequency Instability in a Modified Penning Discharge (Q-PIG)
Authors: Klan F . 
Published: February 2015

Abstract
Low frequency oscillations observed in a modified PIG discharge were identified as fluctuations of the electron temperature. These oscillations only occurred under certain conditions (low gas pressure, relatively high magnetic field), whereas at high pressure and low magnetic field strength the plasma was remarkably stable; this is why the discharge is referred to as a "quiescent" PIG (Q-PIG) discharge. This paper describes measurements for obtaining a detailed picture of the two modes of the discharge. A qualitative explanation of the phenomena observed is obtained using the energy balance of the electron gas.
Eine direkte Bestimmung der Primärprodukte von Radikal-Molekül-Reaktionen: OH+C2H2→CO+CH3 und OH+N2H4→NH3+NH2O
Authors: Gehring M. , Hoyermann K. , Wagner H. Gg. , Wolfrum J. 
Published: February 2015

Using crossed nozzle beam technique, the primary products of OH reactions with acetylen and hydrazine were determined without subsequent steps, giving
OH + C2H2 → CO + CH3,
OH + N2H4 → NH2O + NH3.
Nachweis von organischen Molekülkomplexen über deren negative Ionen
Authors: Knof Hans , Kraft Dieter 
Published: February 2015

Abstract
Molecular polymeres of organic compounds could be identified with a special mass spectrometer by their negative ions without fragmentation from acetone, methanol, and formic acid. Verification of these measurements was obtained by the investigation of deuterated samples. Molecular ions were measured up to trimers. Benzene and cyclohexane did not show polymer ions. The measured pressure dependence indicates preference of electron attachment in ion production against ion molecule reactions. The complexes are held together by the intermolecular dipole forces.
Der Debye-Sears-Effekt zur Bestimmung der elastischen Konstanten von Silicium
Authors: Metzger H. , Kessler F. R. 
Published: February 2015

Abstract
Der Debye-Sears-Effekt (Lichtbeugung an Ultraschallwellen) wird als Methode zur Bestimmung der elastischen Konstanten auf den nahen ultraroten Spektralbereich ausgedehnt und auf Silicium angewendet. Als Lichtquelle dient ein He-Ne-Gaslaser mit einer Wellenlänge von 1,1523 μm. Die Ultraschallfrequenz liegt bei 57 MHz.
Für die Intensitätsverhältnisse des gebeugten Lichtes läßt sich die Raman-Nathsche Theorie des Phasengitters benutzen; hieraus können die vorliegenden Brechungsindexschwankungen bestimmt werden.
Die 7 kristallographisch verschiedenen Schallgeschwindigkeiten bzw. die 3 elastischen Konstanten des Siliciums werden angegeben und den aus Impulsmeßverfahren bekannten Literaturwerten vergleichend gegenübergestellt.
Aus der Resonanzverstimmung bei optisch gemessener Temperaturerhöhung gelingt es, die Temperaturkoeffizienten der Schallgeschwindigkeiten zu messen und daraus die Temperaturkoeffizienten der elastischen Konstanten zu berechnen.
Temporal Development of Giant Pulses in Passively Q-switched Laser Oscillators
Authors: Darée K. , Puell H. 
Published: February 2015

Abstract
The development of giant pulses in a passively Q-switched laser oscillator has been investigated in the case of a high power, multimode system. An experimental technique is described which allows the study of the pulse development over more than two decades of laser power. For powers ≲ 0.1 maximum power an exponential increase of light flux is found. The time constant of this exponential part is calculated, and the relevant parameters are discussed. Calculated and measured time constants are in satisfactory agreement. In addition, it is shown that there is a connexion between the risetime of the pulse and the output energy, power, and divergence of the laser beam. As an example, the optimalization of a laser system for microplasma production is considered.
Spektroskopische Untersuchung von Hetero-Excimeren mit heterozyklischen aromatischen Kohlenwasserstoffen als Elektronakzeptoren
Authors: Rehm Dieter 
Published: February 2015

Abstract
Heterocyclic aromatic hydrocarbons form hetero-excimers with electron donors. The correlation which exists between the energy corresponding to the complex emission maximum and the redoxpotentials of acceptors and donors shows that charge-transfer interaction is predominant in these hetero-excimers.
For some complexes the thermodynamic parameters of complex formation as well as the dipole moments in the excited state are reported.
Microwave Relaxation and Association of 3,5 Dimethyl 3-Hexanol
Authors: Hanna F. F. , Abd-El-Nour K. N. 
Published: February 2015

Abstract
The dielectric constant (ε′) and dielectric loss (ε′′) of 3,5 dimethyl 3-hexanol in heptane have been measured for dilute and concentrated solutions at five wavelengths between 25 cm and 2 mm and at 20°, 40° and 60 °C. The data have been analysed and two relaxation times are obtained. The long relaxation time is attributed to the rotation of the whole molecule and the short relaxation time to the relaxation of the OH-group. For the range of concentrations used, the results show that associates are hardly detectable.
Berechnung der Elektronendichte von Alkanen nach dem S-DIAG-Verfahren zur Interpretation chemischer Verschiebungen
Authors: Janoschek R. 
Published: February 2015

Abstract
Mit dem nichtempirischen Verfahren S-DIAG werden unter Verwendung sphärischer Gauß-Funktionen die Elektronendichten an den Kohlenstoffkernen und an den Protonen einiger Alkane berechnet. Im Gegensatz zu semiempirischen Verfahren liefern die hier berechneten Elektronendichten im Gang vollkommene Übereinstimmung mit den gemessenen chemischen Verschiebungen.
Quantitative Zerlegung binärer Legierungsschmelzen in verschiedene Strukturanteile /A Method for Quantitative Subdivision of a Two-Component Melt or a Two-Component Amorphous Substance Into Their Structural Constituents by Diffraction Experiments
Authors: Steeb S. , Bühner H . F . 
Published: February 2015

Based on the experimental fact that the average coordination number in a binary liquid alloy is not constant, a refined model for the structure of such melts consists of two structural fractions: a) one which shows the same partial coordination number as the relevant solid intermetallic compound and
b) the other, in which the atoms of both kinds are distributed at random. The application of this model to previous X-ray diffraction measurements on Mg -Sn, Mg -Pb, Mg -Ag, and Au-Al alloys permits to subdivide the respective melts into the structural fractions mentioned above.
The partial concentrations are plotted vs. the total concentrations. Finally, it is pointed out that the same method may be employed to determine the crystalline fraction in amorphous solids and in liquid semi-conductors quantitatively.
Adsorption von CO auf einer Palladium(111)-Oberfläche
Authors: Ertl G. , Koch J. 
Published: February 2015

Abstract
The adsorption of CO on a clean Pd(lll) surface has been studied by means of low energy electron diffraction (LEED), contact potential measurements and flash desorption. At coverages ㊀ between 1/3 and 1/2 ordered adsorption phases are observed for which structure models are derived. The maximum increase of the work function Δϕ is about 1 eV; Δϕ is proportional to ㊀. Adsorption isotherms have been measured between 100 and 300 °C and the isosteric heat of adsorption Ead has been determined as a function of ㊀. Ead is constant (34 kcal/mole) up to ㊀ = 1/3 and then decreases owing to structural influences and intermolecular interactions.
Die Ionisierungsquerschnitte von Stickstoff-und Halogen-Kohlenwasserstoffderivaten
Authors: Grosse Hans-Jörg , Bothe Hans-Karl 
Published: February 2015

Abstract
Mit einem 1968 beschriebenen Ionisierungsquerschnittsdetektor mit Kr85 -β-Strahlenquelle wurden die relativen Werte der Ionisierungsquerschnitte von Stickstoff-und Halogen-Kohlen-wasserstoffderivaten bestimmt. Führt man empirisch bestimmte "Bindungsquerschnitte" analog zu der früheren Arbeit1 ein, so stimmen die aus „Bindungsquerschnitten“ berechneten Ionisie-rungsquerschnitte innerhalb des Meßfehlers von 2% mit den gemessenen überein. Ein Vergleich der experimentell ermittelten Werte mit den nach den Verfahren von OTVOS und STEVENSON2 (1956), LAMPE, FRANKLIN und FIELD3 (1957) und STEVENSON und SCHISSLER4 (1961) berech-neten Daten zeigt, daß die Methode von OTVOS und STEVENSON zwar die günstigste Übereinstim-mung für eine Reihe von Verbindungen ergibt, die maximale Abweichung bezüglich des experi-mentellen Ionisierungsquerschnittes bei stickstoff-und halogenhaltigen Kohlenwasserstoffderiva-ten jedoch 11,5% bzw. 14,7% beträgt. Die Ursache dieser Abweichungen im Gegensatz zu den aus „Bindungsquerschnitten“ erhaltenen Ionisierungsquerschnitten ist auf die Vernachlässigung des Einflusses der chemischen Bindung auf die Größe des Ionisierungsquerschnittes zurück-zuführen. Die Größe der „Bindungsquerschnitte“ und ihre Anwendungsgesetze können mit Hilfe der Ultraviolett-Absorptionsspektren erklärt werden.
Unelastische Elektronenstreuung an 140Ce bis 3,5 MeV Anregungsenergie
Authors: Pitthan R. 
Published: February 2015

Abstract
From electron scattering experiments (scattering angle 141°, primary energies 60 and 50 MeV) ground state radiation widths were determined for the levels at 1.60 (2+), 2.08 (4+), 2.46 (3-), 2.90, 3.12, and 3.32 MeV.
Spins and parities of the last three levels which were known as 1+ or 2+, could be classified as 2 +.
Self-diffusion in Molten Silver Iodide
Authors: Andréasson Dan , Behn Anders , Sjöblom Carl-Axel 
Published: February 2015

Abstract
The self-diffusion coefficients of the cation (D+) and of the anion (D-) have been measured in molten silver iodide be­ tween 580 °C and 620 °C with the porous-frit technique. At 610 °C it is found that D+ = D-=5A × 10-5 cm2 s-1. At the melting point (556 °C) D+ melt (4.4 × 10-5 cm2 s-1) is very close to D+ solid (4.3 × 10-5 cm2 s-1) . The Klemm friction coefficients do not indicate the existence of complex entities. D+ and D- calculated according to the Nernst-Einstein equation agree with observed data within 20%.
Lorentz-und metrikinvariante Skalare
Authors: Fleischmann R. 
Published: February 2015

Abstract
Auf die Sonderstellung der metrikinvarianten (universell gequantelten) Skalare der Physik wird hingewiesen. Aus ihnen können die übrigen Größen definiert werden mit Hilfe von Länge und Zeit. Eine bevorzugte Stellung haben die alternierenden Differentialformen, weil sie sich als Ganzes wie metrikinvariante Skalare verhalten. Der Begriff orthogonal geht nicht ein.