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  • 1
    Electronic Resource
    Electronic Resource
    Analysis of longitudinal mode wave guiding in vertical-cavity surface-emitting lasers with long monolithic cavity (2001)
    Woodbury, NY : American Institute of Physics (AIP)
    Applied Physics Letters 78 (2001), S. 586-588 
    Details
    ISSN: 1077-3118
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Lasing mode switching between two longitudinal modes is observed in transverse single mode vertical-cavity surface-emitting lasers with an extended cavity. Near- and far-field analyses carried out on devices with 2, 4, and 8 μm cavity spacers show an inherent relation between the transverse mode diameter and the calculated oxide- or thermally induced index guiding for the oscillating modes. Depending on the designed alignment of the optical longitudinal standing wave patterns relative to the oxide layer, mode switching can either be promoted or suppressed. Record-high single mode output powers up to 5.5 mW obtained from devices with 8 μm spacers and 8μm active diameter indicate the potential of the given device concept for low-divergence fundamental mode emission as required for many applications. © 2001 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.1344569
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  • 2
    Electronic Resource
    Electronic Resource
    Time-resolved dissociative intense-laser field ionization for probing dynamics: Femtosecond photochemical ring opening of 1,3-cyclohexadiene (2000)
    College Park, Md. : American Institute of Physics (AIP)
    The Journal of Chemical Physics 112 (2000), S. 8347-8362 
    Details
    ISSN: 1089-7690
    Source: AIP Digital Archive
    Topics: Physics , Chemistry and Pharmacology
    Notes: The concerted photochemical ring opening of 1,3-cyclohexadiene was investigated in the gas phase by low-intensity pumping at 267 nm and subsequent probing by high-intensity photoionization at 800 nm and mass-selective detection of the ion yields. We found five different time constants which can be assigned to traveling times along consecutive parts of the potential energy surfaces. The molecule is first accelerated in the spectroscopic state 1B along Franck–Condon active coordinates, then alters direction before changing over to the dark state 2A. All constants including that for leaving the 2A surface are below 100 fs. These times are shorter than appropriate vibrational periods. Such a maximum speed is evidence that the pathway is continuous leading from surface to surface via real crossings (conical intersections) and that the molecule is accelerated right into the outlet of the 2A/1A funnel. On the ground state it arrives as a compact wave packet, indicating a certain degree of coherence. The experimental method promises a high potential for investigating dynamics, since many consecutive phases of the process can be detected. This is because the fragmentation pattern depends on the location on the potential energy surface, so that monitoring several different ions permits to conclude on the population flow through these locations. Ionization at the intensities used is normally considered to be an effect of the electric field of the radiation. But in our case it is enhanced by resonances in the neutral molecule and in particular in the singly positive ion, and it is not sensitive for the length of the molecule (different conformers of the product hexatriene). The ionic resonances explain why hexatriene has a much richer fragmentation pattern than cyclohexadiene. Coulomb explosion is observed from an excited state of a doubly positive ion. Its mechanism is discussed. © 2000 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.481478
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  • 3
    Electronic Resource
    Electronic Resource
    Low temperature properties of (La, Nd)Sn3 alloys (1979)
    Springer
    The European physical journal 34 (1979), S. 65-77 
    Details
    ISSN: 1434-6036
    Source: Springer Online Journal Archives 1860-2000
    Topics: Physics
    Notes: Abstract Dilute (La1−x Nd x )Sn3 alloys with 0.01〈x〈0.15 are characterized by determination of the superconducting transition temperatureT c as well as low temperature measurements of the specific heat and inelastic neutron scattering. As an important result of these experiments we found that the Nd impurities in LaSn3 exist as stable trivalent ions, in contrast to all other light rare earths. In addition, specific heat and neutron scattering results revealed the scheme of crystal field (CF) levels of Nd3+. Using this level scheme, the concentration dependence of the superconducting transition temperature,T c (x), could be quantitatively fitted up tox≃9 at % by the theory of Keller and Fulde [J. Low. Temp. Phys.4, 289 (1971)]. From the relatively high initial slope ofT c (x) we inferred that — besides isotropic spin exchange — other pair-breaking processes are important. In contrast toT c (x), the reduced specific heat jumpsΔC/ΔC 0 as a function ofT c /T c0 (whereT c0 andΔC 0 refer to LaSn3) were found to lie considerably below the theoretical curve for isolated Nd3+ ions. This is explained by Nd—Nd interactions resulting in a mean Zeeman splitting (〈k B T c ) of the CF ground state, which could be directly observed in the form of broadened Schottky humps in the normal state specific heats.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01362780
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  • 4
    Electronic Resource
    Electronic Resource
    Triploidie als Ursache von Schwangerschaftsgestose im 2. Trimenon (1975)
    Springer
    Archives of gynecology and obstetrics 218 (1975), S. 113-123 
    Details
    ISSN: 1432-0711
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Description / Table of Contents: Zusammenfassung Ein Fall von kindlicher Triploidie wird vorgestellt. Die Schwangerschaft war gekennzeichnet durch therapieresistente EPH-Gestose im 2. Trimenon mit Übergang in Präeklampsie in der 33. Woche. Der durch Sectio entbundene, nicht lebensfähige Fetus war äußerlich weiblich, untergewichtig, hypoton und asphyktisch. Er wies eine Hirnmißbildung mit Kebozephalie, einem großen univentrikulären Hohlraum und Fehlen der Hypophyse sowie multiple Mißbildungen und dysmorphe Zeichen auf. Bei der Sektion fanden sich Hypo- und Dysplasie der Nebennieren; Uterus, Tuben und Ovarien waren nicht angelegt, Testes waren nicht nachweisbar. Die Plazenta war auffallend groß und zeigte herdförmige hydatidiforme Degenerationen der Zotten. Der Karyotyp war 69,XXY, und mit Hilfe der Fluoreszenzmarker ließ sich der väterliche Ursprung des überzähligen haploiden Satzes nachweisen. Die für Triploidie typischen Schwangerschaftsbefunde werden besprochen und auf die Möglichkeit der pränatalen Diagnose durch Chromosomenuntersuchung an gezüchteten Zellen der Amnionflüssigkeit wird hingewiesen.
    Notes: Summary The authors report a case of triploidy in a prematurely born child. The pregnancy was complicated by severe toxemia beginning during the second trimester and terminating in preeclampsia leading to cesarian section in the 33th week of gestation. The externally female child was underweight, hypotonic and asphyctic and died shortly after birth. She exhibited a complex brain malformation including excessive hydrocephaly, cebocephaly and aplasia of the piturary gland, and multiple dysmorphic signs. Autopsy revealed hypoplasia and dysplasia of the adrenal glands; no uterus, tubes and ovaries were present, but no testes were found. The placenta showed localized hydatidiform degeneration and was relatively large. The karyotype was 69,XXY, and with the aid of fluorescence markers, paternal origin of the additional haploid chromosome set was demonstrated. Typical findings in pregnancies with fetal triploidy are discussed and the possibility of prenatal diagnosis of triploidy by chromosome analysis in cultivated amniotic fluid cells is pointed out.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01395911
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  • 5
    Electronic Resource
    Electronic Resource
    IR absorption of highly vibrationally excited SF6 (1978)
    Springer
    Applied physics 15 (1978), S. 297-301 
    Details
    ISSN: 1432-0630
    Keywords: 33
    Source: Springer Online Journal Archives 1860-2000
    Topics: Mechanical Engineering, Materials Science, Production Engineering, Mining and Metallurgy, Traffic Engineering, Precision Mechanics , Physics
    Notes: Abstract In a double-resonance experiment, the absorption of various CO2 laser lines by sulfur hexafluoride was measured, before and after the SF6 was pumped by a fixed frequency CO2 laser to a level of 5 quanta/molecule. The absorption is substantially shifted to longer wavelengths. But the short wavelength wing of the absorption band is not completely bleached. Instead a shoulder of several cm−1 width is left. This shoulder is probably important for the explanation of the infrared laser induced dissociation of SF6.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00896111
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  • 6
    Electronic Resource
    Electronic Resource
    Plan for the swiss randomized hail suppression experiment. Design of Grossversuch IV (1978)
    Springer
    Pure and applied geophysics 117 (1978), S. 548-571 
    Details
    ISSN: 1420-9136
    Keywords: Hail prevention ; Randomized seeding ; Statistical design
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract An experimental research program is described which investigates the possibility of reducing hailfall in an area of 1000 km2 using the Moldavian rocket seeding method. It involves a design in which experiments are randomized (50∶50) by day over a fixed experimental area. The evaluation is based on data collected during the experimental unit (12–2100 hours). The test variable is hail kinetic energy measured by hailpads and by a hailpad-adjusted S-band radar. A description of the experimental area, the instrumentation and the seeding method adapted from the Soviet Union as well as calculations of the nuclei plume behaviour after seeding with large Oblako rockets are presented. The statistical design is given as well as an extensivea priori description of the confirmatory evaluation procedure which will be used to prove an eventual seeding effect. It is recognized that good predictors are essential to arrive at a statistically significant results in 5 years. From synoptic and radar data obtained during the preliminary phase of the experiment a predictor function is derived. A concomitant variable (cloud base temperature) is proposed taking into account a possibly variable reaction of different storm types to the seeding. The development of the statistical test to be used is also described. Section 7 indicates some possibilities for further exploratory analyses with emphasis on hailpad measurements.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00876634
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  • 7
    Electronic Resource
    Electronic Resource
    Trisomy 6q25→6qter in a severely retarded 7-year-old boy with turricephaly, bow-shaped mouth, hypogenitalism and club feet (1979)
    Springer
    Human genetics 〈Berlin〉 46 (1979), S. 279-284 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Trisomy for a small terminal segment of chromosome 6q produces a characteristic syndrome of malformations and dysmorphic signs which, on the basis of comparison with a previously published case, may be suspected on clinical grounds. The present case concerns a 7-year-old boy, the son of a carrier mother t(6;14)(q25;qter). The main symptoms are: very severe physical and mental retardation, turricephaly, Cupid's bow mouth with narrow lips, almond-shaped eyes with narrow palpebral fissures and ptosis, micropenis with absence of scrotum, club feet, hammer toes, and extension contractures. In addition, there are a great many minor dysmorphic features.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00273311
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  • 8
    Electronic Resource
    Electronic Resource
    Trisomy for the distal third of the long arm of chromosome 19 in brother and sister (1979)
    Springer
    Human genetics 〈Berlin〉 46 (1979), S. 263-270 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Trisomy for the distal third of the long arm of chromosome 19 was observed in a 12-year-old boy and his 9-year-old sister. Both are affected by extremely severe statural and psychomotor retardation. The physical symptoms common to both are dwarfism, micro- and brachycephaly, antimongoloid slant of the eyes, hypertelorism, ptosis, short nose, short philtrum, poorly formed ears, short neck with excess skin, barrel-shaped thorax, diastasis of rectus muscles, kyphosis, sacral dimple, excess of digital arches, pedes valgi, laterally curved big toes, epilepsy and muscular hypotonia. The chromosomal anomaly was transmitted by the mother, who is the carrier of a translocation t(19;20)(19q133;20pter). In the pedigree, extending over four generations, among 30 pregnancies fathered or mothered by 5 carriers resulted in: 6 individuals with normal karyotype, 9 carriers, 2 confirmed and 2 presumptive unbalanced abnormal children, and 10 abortions.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00273309
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  • 9
    Electronic Resource
    Electronic Resource
    Further delineation of the clinical picture of trisomy for the distal segment of chromosome 13 (1976)
    Springer
    Human genetics 〈Berlin〉 32 (1976), S. 1-12 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary Three cases of partial trisomy for the distal segment of chromosome 13 are reported. Common clinical features included normal birth weight, postnatal asphyxia, convulsions, severe psychomotor retardation, normal growth, and a distinct pattern of dysmorphias consisting of trigonocephalic head with prominent metopic suture, long and markedly curved eyelashes, a stubby nose, increased distance between nose and upper lip, high-arched palate, misshapen ears with virtually absent lobules and prominent anthelices which are curved in a sharp angle, and hemangiomata. Features present in 2 cases were microcephaly, long and narrow fingers with convex nails, and hexadactyly. Two cousins were unbalanced offspring of a large family of carriers of a 9/13 translocation, whereas the third case exhibited a 13p+ chromosome which was formed de novo. The clinical features in the 3 patients are typical of the syndrome due to partial trisomy for the distal segment of chromosome 13 which shows selected and mitigated signs of full trisomy 13.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00569970
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  • 10
    Electronic Resource
    Electronic Resource
    Centromere inactivation in a case of turner variant with two dicentric iso-long arm Y chromosomes (1978)
    Springer
    Human genetics 〈Berlin〉 41 (1978), S. 217-223 
    Details
    ISSN: 1432-1203
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Summary A 6-year-old girl of small stature and with some features of Turner's syndrome was found to have a karyotype with two-thirds of the cells possessing one, and one-third with two dicentric iso-long arm Y chromosomes. In metaphases with 46 chromosomes the majority of the abnormal Ys exhibited two primary constrictions. In cells with 47 chromosomes both isochromosomes prevalently had only one active centromere.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00273104
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