Der Affekt des vermeintlichen Siegers: Zu Hauke Brunkhorsts Auseinandersetzung mit Antiintellektualismus und Konservatismus

Die Tagesordnung der politischen Diskussion wird seit geraumer Zeit nicht mehr von der kritischen Intelligenz festgelegt. Die »Themenführerschaft« wurde an die Neokonservativen abgegeben. Ist dies bloß das (letzte) Aufbäumen der »deutschen Manadarine« gegen die im Zuge der Demokratisierung erfolgte gesellschaftliche Institutionalisierung der Rolle kritischer Intellektueller, die ihren entscheidenden Schub in den sechziger Jahren erhielt - wie dies Hauke Brunkhorst behauptet- oder spiegelt sich darin vielmehr eine Krise des Projekts der Modeme wider, die auch Position und Funktion der kritischen Intellektuellen umfaßt? Der Neokonservatismus kann auf tiefgreifende gesellschaftliche Enwicklungen bauen. Insbesondere die Gruppe der »Modernitätstraditionalisten« hat ein analytisches Instrumentarium entwickelt, mit dem sie die Ambivalenz der kulturellen Prozesse der achtziger Jahre erfassen und auf die sie ideologisch-politisch einwirken kann. Eine Geringschätzung des westdeutschen Neokonservatismus durch kritische Intellektuelle ist irreführend

Intrinsic energy flow in laser-excited 3d ferromagnets

Ultrafast magnetization dynamics are governed by energy flow between electronic, magnetic, and lattice degrees of freedom. A quantitative understanding of these dynamics must be based on a model that agrees with experimental results for all three subsystems. However, ultrafast dynamics of the lattice remain largely unexplored experimentally. Here we combine femtosecond electron diffraction experiments of the lattice dynamics with energy-conserving atomistic spin dynamics (ASD) simulations and ab initio calculations to study the intrinsic energy flow in the 3d ferromagnets cobalt (Co) and iron (Fe). The simulations yield a good description of experimental data, in particular an excellent description of our experimental results for the lattice dynamics. We find that the lattice dynamics are influenced significantly by the magnetization dynamics due to the energy cost of demagnetization. Our results highlight the role of the spin system as the dominant heat sink in the first hundreds of femtoseconds. Together with previous findings for nickel [Zahn et al., Phys. Rev. Research 3, 023032 (2021)], our work demonstrates that energy-conserving ASD simulations provide a general and consistent description of the laser-induced dynamics in all three elemental 3d ferromagnets

Three hundred eighty thousand year long stable isotope and faunal records from the Red Sea : influence of global sea level change on hydrography

Stable isotope and faunal records from the central Red Sea show high-amplitude oscillations for the past 380,000 years. Positive δ18O anomalies indicate periods of significant salt buildup during periods of lowered sea level when water mass exchange with the Arabian Sea was reduced due to a reduced geometry of the Bab el Mandeb Strait. Salinities as high as 53‰ and 55‰ are inferred from pteropod and benthic foraminifera δ18O, respectively, for the last glacial maximum. During this period all planktonic foraminifera vanished from this part of the Red Sea. Environmental conditions improved rapidly after 13 ka as salinities decreased due to rising sea level. The foraminiferal fauna started to reappear and was fully reestablished between 9 ka and 8 ka. Spectral analysis of the planktonic δ18O record documents highest variance in the orbital eccentricity, obliquity, and precession bands, indicating a dominant influence of climatically - driven sea level change on environmental conditions in the Red Sea. Variance in the precession band is enhanced compared to the global mean marine climate record (SPECMAP), suggesting an additional influence of the Indian monsoon system on Red Sea climates

Heat and Charge Transport Properties of MgB2

A polycrystalline sample of the MgB_2 superconductor was investigated by measurements of the electrical resistivity, the thermopower and the thermal conductivity in the temperature range between 1.8K and 300K in zero magnetic field. The electrical resistivity shows a superconducting transition at T_c=38.7K and, similarly to borocarbides, a T^2.4 behaviour up to 200K. The electron diffusion thermopower and its bandstructure-derived value indicate the dominant hole character of the charge carriers. The total thermopower can be explained by the diffusion term renormalized by a significant electron-phonon interaction and a phonon drag term. In the thermal conductivity, for decreasing temperature, a significant decrease below T_c is observed resulting in a T^3 behaviour below 7K. The reduced Lorenz number exhibits values smaller than 1 and a characteristic minimum which resembles the behaviour of non-magnetic borocarbides.Comment: 7 pages, 5 figures; added references and minor changes; accepted for publication in Physica

Lattice dynamics and ultrafast energy flow between electrons, spins, and phonons in a 3d ferromagnet

The ultrafast dynamics of magnetic order in a ferromagnet are governed by the interplay between electronic, magnetic, and lattice degrees of freedom. In order to obtain a microscopic understanding of ultrafast demagnetization, information on the response of all three subsystems is required. A consistent description of demagnetization and microscopic energy flow, however, is still missing. Here, we combine a femtosecond electron diffraction study of the ultrafast lattice response of nickel to laser excitation with ab initio calculations of the electron-phonon interaction and energy-conserving atomistic spin dynamics simulations. Our model is in agreement with the observed lattice dynamics and previously reported electron and magnetization dynamics. Our approach reveals that the spin system is the dominating heat sink in the initial few hundred femtoseconds and implies a transient nonthermal state of the spins. Our results provide a clear picture of the microscopic energy flow between electronic, magnetic, and lattice degrees of freedom on ultrafast timescales and constitute a foundation for theoretical descriptions of demagnetization that are consistent with the dynamics of all three subsystems

Strong impact of wildfires on the abundance and aging of black carbon in the lowermost stratosphere

Wildfires inject large amounts of black carbon (BC) particles into the atmosphere, which can reach the lowermost stratosphere (LMS) and cause strong radiative forcing. During a 14-month period of observations on board a passenger aircraft flying between Europe and North America, we found frequent and widespread biomass burning (BB) plumes, influencing 16 of 160 flight hours in the LMS. The average BC mass concentrations in these plumes (∼140 ng·m$^{-3}$, standard temperature and pressure) were over 20 times higher than the background concentration (∼6 ng·m$^{-3}$) with more than 100-fold enhanced peak values (up to ∼720 ng·m$^{-3}$). In the LMS, nearly all BC particles were covered with a thick coating. The average mass equivalent diameter of the BC particle cores was ∼120 nm with a mean coating thickness of ∼150 nm in the BB plume and ∼90 nm with a coating of ∼125 nm in the background. In a BB plume that was encountered twice, we also found a high diameter growth rate of ∼1 nm·h$^{-1}$ due to the BC particle coatings. The observed high concentrations and thick coatings of BC particles demonstrate that wildfires can induce strong local heating in the LMS and may have a significant influence on the regional radiative forcing of climate