Quantitative Rescattering Theory for high-order harmonic generation from molecules

The Quantitative Rescattering Theory (QRS) for high-order harmonic generation (HHG) by intense laser pulses is presented. According to the QRS, HHG spectra can be expressed as a product of a returning electron wave packet and the photo-recombination differential cross section of the {\em laser-free} continuum electron back to the initial bound state. We show that the shape of the returning electron wave packet is determined mostly by the laser only. The returning electron wave packets can be obtained from the strong-field approximation or from the solution of the time-dependent Schr\"odinger equation (TDSE) for a reference atom. The validity of the QRS is carefully examined by checking against accurate results for both harmonic magnitude and phase from the solution of the TDSE for atomic targets within the single active electron approximation. Combining with accurate transition dipoles obtained from state-of-the-art molecular photoionization calculations, we further show that available experimental measurements for HHG from partially aligned molecules can be explained by the QRS. Our results show that quantitative description of the HHG from aligned molecules has become possible. Since infrared lasers of pulse durations of a few femtoseconds are easily available in the laboratory, they may be used for dynamic imaging of a transient molecule with femtosecond temporal resolutions.Comment: 50 pages, 15 figure

Potential for ultrafast dynamic chemical imaging with few-cycle infrared lasers

We studied the photoelectron spectra generated by an intense few-cycle infrared laser pulse. By focusing on the angular distributions of the back rescattered high energy photoelectrons, we show that accurate differential elastic scattering cross sections of the target ion by free electrons can be extracted. Since the incident direction and the energy of the free electrons can be easily changed by manipulating the laser's polarization, intensity, and wavelength, these extracted elastic scattering cross sections, in combination with more advanced inversion algorithms, may be used to reconstruct the effective single-scattering potential of the molecule, thus opening up the possibility of using few-cycle infrared lasers as powerful table-top tools for imaging chemical and biological transformations, with the desired unprecedented temporal and spatial resolutions.Comment: 16 pages, 6 figure

Über experimentelle Serumkrankheiten von Kaninchen. (I. Mitteilung)

Über Serumkrankheiten wurde bisher von klinischer Seit viel berichtet, aber es fehlen Arbeiten über Tierversuche auf diesem Gebiet. Daher stellte Verfasser Versuch über Serumkrankheiten in systematischer Weise mit Pferd- und Rinderserum bei Kaninchen und Meerschweinchen an. Hier seien die Resultate kurz zusammengefasst angeben. Als Versuchtiere wählte Verfasser weisse Kaninchen, weil die Rötung nach der Seruminjektion und der Eautöedem auf beiden Ohren leicht bemerkbar sind. 1) Von 92 Kaninchen bekam er positive Reaktionen in 57 Fallen nach Injektion mit grossen Pferdserum intravenos, subkutan und intraperitoneal. 2) Die nötige Menge zur Injektion betrug über 5cc pro Kilogramm des Versuchtiers, weil unter dieser Menge (3 od. 4cc) der Versuch immer negativ bleibt, und 5cc Injektion zu 48%, 6cc zu 76%, 10cc zu 57% positiv reagiert. 3) Es ist interessant, dass diese Reaktion nach bestimmter Inkubation auftritt, nach 4 Tagen in 4 Fällen, 5 Tagen in 19 und nach 6 Tagen in 25 Fällen (Hochstzahl), dann wieder abnehmend nach 7 Tagen in 7, nach 8 Tagen in 2 Fällen. 4) Die positive Reaktion dauert über 3 Tagen bis zu 7 Tagen und bei leichten Symptomen bis zu 3 Tagen, 5) Diese Reaktion schwankt je nach der Individualität der Versuchkaninchen und noch stärker je nach den Pferserumarten. Aktives frisches Serum wirkt stärker als inaktives. Doch wurde positive Reaktion mit 3 Jahren alten Pferdsera erzielt. 6) Nach Rinderseruminjektion reagiert das Tier etwas milder als mit Pferdserum; durch beide Serumarten wurde auch beim Meerschweinchen positive Reaktion erreicht. 7) Ausser Hautrötung und Hautöedem stellt man bei positiven Serumkrankheiten des Versuchtiers Temperatursteigerung (2-3 C°) und Leukozytose fest

Divergent effects of urban particulate air pollution on allergic airway responses in experimental asthma: a comparison of field exposure studies

Abstract Background Increases in ambient particulate matter of aerodynamic diameter of 2.5 μm (PM2.5) are associated with asthma morbidity and mortality. The overall objective of this study was to test the hypothesis that PM2.5 derived from two distinct urban U.S. communities would induce variable responses to aggravate airway symptoms during experimental asthma. Methods We used a mobile laboratory to conduct community-based inhalation exposures to laboratory rats with ovalbumin-induced allergic airways disease. In Grand Rapids exposures were conducted within 60 m of a major roadway, whereas the Detroit was located in an industrial area more than 400 m from roadways. Immediately after nasal allergen challenge, Brown Norway rats were exposed by whole body inhalation to either concentrated air particles (CAPs) or filtered air for 8 h (7:00 AM - 3:00 PM). Both ambient and concentrated PM2.5 was assessed for mass, size fractionation, and major component analyses, and trace element content. Sixteen hours after exposures, bronchoalveolar lavage fluid (BALF) and lung lobes were collected and evaluated for airway inflammatory and mucus responses. Results Similar CAPs mass concentrations were generated in Detroit (542 μg/m3) and Grand Rapids (519 μg/m3). Exposure to CAPs at either site had no effects in lungs of non-allergic rats. In contrast, asthmatic rats had 200% increases in airway mucus and had more BALF neutrophils (250% increase), eosinophils (90%), and total protein (300%) compared to controls. Exposure to Detroit CAPs enhanced all allergic inflammatory endpoints by 30-100%, whereas inhalation of Grand Rapids CAPs suppressed all allergic responses by 50%. Detroit CAPs were characterized by high sulfate, smaller sized particles and were derived from local combustion sources. Conversely Grand Rapids CAPs were derived primarily from motor vehicle sources. Conclusions Despite inhalation exposure to the same mass concentration of urban PM2.5, disparate health effects can be elicited in the airways of sensitive populations such as asthmatics. Modulation of airway inflammatory and immune responses is therefore dependent on specific chemical components and size distributions of urban PM2.5. Our results suggest that air quality standards based on particle speciation and sources may be more relevant than particle mass to protect human health from PM exposure.http://deepblue.lib.umich.edu/bitstream/2027.42/112357/1/12940_2012_Article_573.pd

Energy End-Use Technologies for the 21st Century. A Report of the World Energy Council

This report makes clear the opportunities and places technology development firmly centre stage in meeting and overcoming the challenges confronting the energy industry and policy makers. Energy End-Use Technologies for the 21st Century makes it crystal clear that technologies deployed in 20 to 50 years will be the result of policy and funding decisions taken now and that we cannot afford to duck these decisions if we are to meet the World Energy Council’s goals of energy availability, accessibility and acceptability

Hadronic Masses and Regge Trajectories

A comprehensive phenomenological analysis of experimental data and some theoretical models is presented here (for mesons) to critically discuss how Regge trajectory parameters depend on flavor. Through analytic continuation of physical trajectories (obtained from resonance data) into the space like region, we derive the suppression factor for heavy flavor production. The case of our D Regge exchange, both for D and $\Lambda_c$ production, is considered in some detail. Good agreement with data is reached confirming that indeed the slopes of heavier flavors decrease. This result suggests that the confinement potential has a substantial dependence on the quark masses. In a simple non-relativistic model, constrained to produce linear Regge trajectories, it is shown that a linear quark mass dependence is required (in the confinement part of the potential) in order for the slope to decrease in the appropriate way.Comment: 19 pages, 9 Figures, IV Table

First Results from the KMOS Lens-Amplified Spectroscopic Survey (KLASS): Kinematics of Lensed Galaxies at Cosmic Noon

We present the first results of the KMOS Lens-Amplified Spectroscopic Survey (KLASS), a new ESO Very Large Telescope (VLT) large program, doing multi-object integral field spectroscopy of galaxies gravitationally lensed behind seven galaxy clusters selected from the HST Grism Lens-Amplified Survey from Space (GLASS). Using the power of the cluster magnification we are able to reveal the kinematic structure of 25 galaxies at $0.7 \lesssim z \lesssim 2.3$, in four cluster fields, with stellar masses $8 \lesssim \log{(M_\star/M_\odot)} \lesssim 11$. This sample includes 5 sources at $z>1$ with lower stellar masses than in any previous kinematic IFU surveys. Our sample displays a diversity in kinematic structure over this mass and redshift range. The majority of our kinematically resolved sample is rotationally supported, but with a lower ratio of rotational velocity to velocity dispersion than in the local universe, indicating the fraction of dynamically hot disks changes with cosmic time. We find no galaxies with stellar mass $<3 \times 10^9 M_\odot$ in our sample display regular ordered rotation. Using the enhanced spatial resolution from lensing, we resolve a lower number of dispersion dominated systems compared to field surveys, competitive with findings from surveys using adaptive optics. We find that the KMOS IFUs recover emission line flux from HST grism-selected objects more faithfully than slit spectrographs. With artificial slits we estimate slit spectrographs miss on average 60% of the total flux of emission lines, which decreases rapidly if the emission line is spatially offset from the continuum.Comment: Accepted for publication in Ap