40 research outputs found
Experimental Characterization Of The Weakly Anisotropic CN X(2)Σ(+) + Ne Potential From IR-UV Double Resonance Studies Of The CN-Ne Complex
IR-UV double resonance spectroscopy has been used to characterize hindered internal rotor states (n(K) = 0(0), 1(1), and 1(0)) of the CN-Ne complex in its ground electronic state with various degrees of CN stretch (nu(CN)) excitation. Rotationally resolved infrared overtone spectra of the CN-Ne complex exhibit perturbations arising from Coriolis coupling between the closely spaced hindered rotor states (1(1) and 1(0)) with two quanta of CN stretch (nu(CN) = 2). A deperturbation analysis is used to obtain accurate rotational constants and associated average CN center-of-mass to Ne separation distances as well as the coupling strength. The energetic ordering and spacings of the hindered internal rotor states provide a direct reflection of the weakly anisotropic intermolecular potential between CN X-2 Sigma(+) and Ne, with only an 8 cm(-1) barrier to CN internal rotation, from which radially averaged anisotropy parameters (V-10 and V-20) are extracted that are consistent for nu(CN) = 0-3. Complementary ab initio calculation of the CN X-2 Sigma(+) + Ne potential using MRCI+Q extrapolated to the complete one-electron basis set limit is compared with the experimentally derived anisotropy by optimizing the radial potential at each angle. Experiment and theory are in excellent accord, both indicating a bent minimum energy configuration and nearly free rotor behavior. Analogous experimental and theoretical studies of the CN-Ne complex upon electronic excitation to the CN B (2)Sigma(+) state indicate a slightly more anisotropic potential with a linear CN-Ne minimum energy configuration. The results from these IR-UV double resonance studies are compared with prior electronic spectroscopy and theoretical studies of the CN-Ne system. (c) 2011 American Institute of Physics. [doi: 10.1063/1.3586810
The Ursinus Weekly, November 14, 1960
Focus on fraternities • Sixteen men accept bids on Nov. 7 to join four of U.C.\u27s local frats • WAA, Woodruff discuss possible ski weekend • Constitution is changed by Curtain Club members • U.C. groups hear Dr. Adams of Yale • Historical article by Dr. Armstrong printed in Church History • Whitians hold tea in Paisley for 50 women • Dr. Zucker to discuss disarming at International Relations Club • Frosh MSGA reps to prepare report on 1960 customs • Y introduces the Aetheneum Society • Juniors present The Bowery November 19 in T-G gym • ICG plans meeting for Nov. 4 in Bomberger chapel at 7 p.m. • Senior Ball set for December 2 • Pre-medders go to AED conference • Young Democrats got out vote, now drive for new membership • Newman Club schedules trip to Greek Catholic church • Bosniak, Dassler are selected 1962 Ruby editors • Harry Sprogall addresses forum • Shaw\u27s Androcles and the Lion subject of English Club meeting • French Club to be shown slides; Field trip discussion planned • Editorial: Forbearance • Letters to the editor • Review of the student concert • Novembers ago • Book review: We the living • Parting political shots: Meeting of minds; Not quite Lincoln and Douglas • Intramural corner • Soccer team drops three close games • Mariners best Bears; U.C. clobbers Fords • Lassies shut out Drexel, Beaver • French film to be shown at Franklin Institutehttps://digitalcommons.ursinus.edu/weekly/1326/thumbnail.jp
Alpha Particle Emission from6He + 209Bi
In a recent experiment, we have for the first time studied near-barrier and sub-barrier fusion of the exotic Borromean nucleus 6He with 209Bi and found that the sub-barrier fusion of this system is exceptionally enhanced, implying a 20% reduction in the nominal fusion barrier. It was suggested that this striking effect might he due to coupling to positive Q-value neutron transfer channels, leading to neutron flow and consequent neck formation between the projectile and target. The results of a new experiment using the radioactive nuclear beam facility at the University of Notre Dame to measure fast ⍺-particle emission from 6He + 209Bi are discussed. A exceptional1y strong transfer/breakup group was observed at near-barrier and sub-barrier energies; this is very likely to be the doorway state that explains the enhanced sub-barrier fusion. In a recent experiment, we have for the first time studied near-barrier and sub-barrier fusion of the exotic Borromean nucleus 6He with 209Bi and found that the sub-barrier fusion of this system is exceptionally enhanced, implying a 20% reduction in the nominal fusion barrier. It was suggested that this striking effect might he due to coupling to positive Q-value neutron transfer channels, leading to neutron flow and consequent neck formation between the projectile and target. The results of a new experiment using the radioactive nuclear beam facility at the University of Notre Dame to measure fast ⍺-particle emission from 6He + 209Bi are discussed. A exceptional1y strong transfer/breakup group was observed at near-barrier and sub-barrier energies; this is very likely to be the doorway state that explains the enhanced sub-barrier fusion
Compton Scattering from the Deuteron Above Pion-Production Threshold
The electromagnetic polarizabilities of the nucleon are fundamental nucleon-structure observables that characterize its response to external electromagnetic fields. The neutron polarizabilities can be accessed from Compton-scattering data on light nuclear targets. Recent measurements of the differential cross section for Compton scattering on the deuteron below the pion-production threshold have decreased the uncertainties in the neutron polarizabilities, yet the proton polarizabilities remain known substantially more accurately. As the sensitivity of the cross section to the polarizabilities increases with incident photon energy, measurements above the pion threshold may offer a way for an improved determination of the neutron polarizabilities. In this Rapid Communiciation, the first measurement of the cross section for coherent Compton scattering on the deuteron above the pion-production threshold is presented
Rapidly Changing Range Limits in a Warming World: Critical Data Limitations and Knowledge Gaps for Advancing Understanding of Mangrove Range Dynamics in the Southeastern USA
Climate change is altering species’ range limits and transforming ecosystems. For example, warming temperatures are leading to the range expansion of tropical, cold-sensitive species at the expense of their cold-tolerant counterparts. In some temperate and subtropical coastal wetlands, warming winters are enabling mangrove forest encroachment into salt marsh, which is a major regime shift that has significant ecological and societal ramifications. Here, we synthesized existing data and expert knowledge to assess the distribution of mangroves near rapidly changing range limits in the southeastern USA. We used expert elicitation to identify data limitations and highlight knowledge gaps for advancing understanding of past, current, and future range dynamics. Mangroves near poleward range limits are often shorter, wider, and more shrublike compared to their tropical counterparts that grow as tall forests in freeze-free, resource-rich environments. The northern range limits of mangroves in the southeastern USA are particularly dynamic and climate sensitive due to abundance of suitable coastal wetland habitat and the exposure of mangroves to winter temperature extremes that are much colder than comparable range limits on other continents. Thus, there is need for methodological refinements and improved spatiotemporal data regarding changes in mangrove structure and abundance near northern range limits in the southeastern USA. Advancing understanding of rapidly changing range limits is critical for foundation plant species such as mangroves, as it provides a basis for anticipating and preparing for the cascading effects of climate-induced species redistribution on ecosystems and the human communities that depend on their ecosystem services
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Tellurite And Fluorotellurite Glasses For Fiberoptic Raman Amplifiers: Glass Characterization, Optical Properties, Raman Gain, Preliminary Fiberization, And Fiber Characterization
In this study we report the physical properties and spontaneous Raman scattering spectra of nine oxide tellurite and fluorotellurite glasses from three glass systems - sodium-zinc-tellurite (TZN), tungsten-tellurite, and fluorotellurite. Raman gain and surface damage threshold at 1064 nm are also shown for a selection of these glasses, which all exhibited high gain and damage resistance. Raman gain spectra were directly measured and accurately calculated for selected TZN and fluorotellurite glasses after Fresnel, internal solid angle, and Bose-Einstein corrections. The calculated gain showed good fits to the Raman gain measurements made using a calibrated nonlinear optics apparatus. Infrared and UV-Vis absorption spectra, characteristic temperatures obtained by differential thermal analysis, densities acquired by the Archimedes principle and refractive indices measured by spectroscopic ellipsometry are also given. The ternary systems TeO2-WO3-Bi2O3 and TeO2-Na2O-ZnF2 and the quaternary system TeO2-Na2O-ZnO-PbO show promise as Raman amplifiers as they are relatively easy to draw into optical fiber and to these authors\u27 knowledge, this is the first time Raman gain has been presented on halide containing tellurite glasses. The oxyfluoride system studied here, TeO2-Na2O-ZnF2, exhibited a dependence on the peak Raman intensity with ZnF2 addition. Calculations of preform geometry for mono- and multimode guidance and stresses in similar and dissimilar (core suction) core-clad pairs are shown. Dispersion in the mid-infrared and initial fiber drawing studies are also reported with fibers showing reasonable unclad losses. © 2007 The American Ceramic Society
G(aksl2): a new cell surface antigen of the mouse related to the dualtropic mink cell focus-inducing class of murine leukemia virus detected by naturally occuring antibody.
Perceptions held by healthcare professionals concerning organ donation after circulatory death in an Australian intensive care unit without a local thoracic transplant service: A descriptive exploratory study
From Craton to Rift: Empirically Based Ground-Truth Criteria for Local Events Recorded on Regional Networks
Region-specific empirically based ground-truth (EBGT) criteria used to estimate the epicentral-location accuracy of seismic events have been developed for the Main Ethiopian Rift and the Tibetan plateau. Explosions recorded during the Ethiopia-Afar Geoscientific Lithospheric Experiment (EAGLE), the International Deep Profiling of Tibet, and the Himalaya (INDEPTH III) experiment provided the necessary GT0 reference events. In each case, the local crustal structure is well known and handpicked arrival times were available, facilitating the establishment of the location accuracy criteria through the stochastic forward modeling of arrival times for epicentral locations. In the vicinity of the Main Ethiopian Rift, a seismic event is required to be recorded on at least 8 stations within the local Pg/Pn crossover distance and to yield a network-quality metric of less than 0.43 in order to be classified as EBGT5(95%) (GT5 with 95% confidence). These criteria were subsequently used to identify 10 new GT5 events with magnitudes greater than 2.1 recorded on the Ethiopian Broadband Seismic Experiment (EBSE) network and 24 events with magnitudes greater than 2.4 recorded on the EAGLE broadband network. The criteria for the Tibetan plateau are similar to the Ethiopia criteria, yet slightly less restrictive as the network-quality metric needs to be less than 0.45. Twenty-seven seismic events with magnitudes greater than 2.5 recorded on the INDEPTH III network were identified as GT5 based on the derived criteria. When considered in conjunction with criteria developed previously for the Kaapvaal craton in southern Africa, it is apparent that increasing restrictions on the network-quality metric mirror increases in the complexity of geologic structure from craton to plateau to rift. Accession Number: WOS:00032256920001