NONLINEAR POLARIZATION SPECTROSCOPY (FREQUENCY DOMAIN) STUDIES OF EXCITED STATE PROCESSES: THE B800–850ANTENNA OF RHODOBACTER SPHAEROIDES

Nonlinear polarization spectroscopy in the frequency domain allows rate constant determinations of fast electronic energy and phase relaxations together with characterization of the type of line broadening. Application of this method to the B850 component of the isolated B800–850antenna ofRhodobacter sphaeroides at room temperature shows that B850 is inhomogeneously broadened, with homogeneous widths between 30 and 200 cm−1, depending on the spectral position of the subforms. The corresponding phase relaxation times are clearly in the subpicosecond range. There is also indication of an up-to-now unspecified1–5 ps energy relaxation channel per subunit

Excitonic coupling dominates the homogeneous photoluminescence excitation linewidth in semicrystalline polymeric semiconductors

We measure the homogeneous excitation linewidth of regioregular poly(3-hexylthiophene), a model semicrystalline polymeric semiconductor, by means of two-dimensional coherent photoluminescence excitation spectroscopy. At a temperature of 8\,K, we find a linewidth that is always $\gtrsim 110$\,meV full-width-at-half-maximum, which is a significant fraction of the total linewidth. It displays a spectral dependence and is minimum near the 0--0 origin peak. We interpret this spectral dependence of the homogeneous excitation linewidth within the context of a weakly coupled aggregate model.Comment: 13 pages, 4 figures, Supplementary Materia

Improved Ultraviolet and Infrared Oscillator Strengths for OH+

Molecular ions are key reaction intermediates in the interstellar medium. OH+ plays a central role in the formation of more complex chemical species and for estimating the cosmic ray ionization rate in astrophysical environments. Here, we use a recent analysis of a laboratory spectrum in conjunction with ab initio methods to calculate infrared and ultraviolet oscillator strengths. These new oscillator strengths include branch dependent intensity corrections, arising from the Herman–Wallis effect, that have not been included before. We estimate 10% total uncertainty in the UV and 6% total uncertainty in the IR for the oscillator strengths

Effects of Kernel Processing at Harvest of Brown Midrib Corn Silage on Finishing Performance of Steers

A 2 × 3 factorial finishing study evaluated kernel processing in three corn silage hybrids on finishing performance of yearling steers fed 40% silage. The three hybrids included a control corn silage (CON), a brown midrib (bm3), and a brown midrib with a softer endosperm (bm3-EXP). No interactions were observed between hybrids and kernel processing (P \u3e 0.45). Feeding both bm3 hybrids increased dry matter intake and average daily gain over CON (P \u3c 0.01). Cattle fed bm3-EXP and bm3 had lower feed to gain than CON (P = 0.04), with no differences between the two brown midrib hybrids. Feeding silage that has undergone kernel processing decreased dry matter intake with similar average daily gain, which decreased feed to gain by 2.6% at 40% inclusion compared to non-processed silage (P = 0.10). The improvement in silage is calculated to be 6.5% (2.6/40) when kernel processing was utilized as compared to not kernel processing the corn silage hybrids

Business aspect

This chapter discusses the business requirements of technology to be developed in support of VEs. It first describes new business directions that have come into existence in the manufacturing industry like the automotive domain. Next, it treats new criteria that have to be met by industries to become or remain successful in new market situations. Finally, new business structures are discussed that (have to) emerge as a consequence of the new directions and criteria

Critical mass and the dependency of research quality on group size

Academic research groups are treated as complex systems and their cooperative behaviour is analysed from a mathematical and statistical viewpoint. Contrary to the naive expectation that the quality of a research group is simply given by the mean calibre of its individual scientists, we show that intra-group interactions play a dominant role. Our model manifests phenomena akin to phase transitions which are brought about by these interactions, and which facilitate the quantification of the notion of critical mass for research groups. We present these critical masses for many academic areas. A consequence of our analysis is that overall research performance of a given discipline is improved by supporting medium-sized groups over large ones, while small groups must strive to achieve critical mass.Comment: 16 pages, 6 figures consisting of 16 panels. Presentation and reference list improved for version

Magnetic Breakdown in the electron-doped cuprate superconductor Nd2−x_{2-x}Cex_xCuO4_4: the reconstructed Fermi surface survives in the strongly overdoped regime

We report on semiclassical angle-dependent magnetoresistance oscillations (AMRO) and the Shubnikov-de Haas effect in the electron-overdoped cuprate superconductor Nd$_{2-x}$Ce$_x$CuO$_4$. Our data provide convincing evidence for magnetic breakdown in the system. This shows that a reconstructed multiply-connected Fermi surface persists, at least at strong magnetic fields, up to the highest doping level of the superconducting regime. Our results suggest an intimate relation between translational symmetry breaking and the superconducting pairing in the electron-doped cuprate superconductors.Comment: 5 pages, 4 figures, submitted to PR