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Zusammenfassung Kommt die Rede auf Proklamationen in „Deutsch-Südwestafrika“, denkt man unweigerlich an den berüchtigten „Aufruf an das Volk der Herero“ des Generalleutnants Lothar von Trotha vom 3. Oktober 1904, der als zentrales Dokument des ersten Genozids des 20. Jahrhunderts gilt. Es fällt in der Tat schwer, sich der Suggestivkraft seiner martialischen wie menschenverachtenden Worte zu entziehen, und zwar umso mehr, wenn man auf die Folgen blickt, die sie über ihre Adressaten, die OvaHerero, bringen sollten. Doch so singulär dieses Dokument in dieser Perspektive auch erscheinen mag, handelte sich dabei um eine eingeschliffene Textform, zu der auch andere militärische wie zivile Spitzenfunktionäre in „Deutsch-Südwestafrika“ vor und nach Trotha griffen. Rückt man Trothas „Aufruf“ in diese Abfolge, kontextualisiert und analysiert ihn, wird deutlich, dass er ursprünglich etwas anderes als ein Dokument des Genozids war, nämlich eine Textform, die über „Deutsch-Südwestafrika“ hinaus für beginnende, despotische Herrschaft typisch ist.

Superconducting nanowire single-photon detectors are an enabling technology for modern quantum information science and are gaining attractiveness for the most demanding photon counting tasks in other fields. Embedding such detectors in photonic integrated circuits enables additional counting capabilities through nanophotonic functionalization. Here we show how a scalable number of waveguide-integrated superconducting nanowire single-photon detectors can be interfaced with independent fiber optic channels on the same chip. Our plug-and-play detector package is hosted inside a compact and portable closed-cycle cryostat providing cryogenic signal amplification for up to 64 channels. We demonstrate state-of-the-art photon counting performance with up to 60 % system detection efficiency and down to 26.0 ps timing accuracy for individually addressable detectors. Our multi-channel single photon receiver offers exciting measurement capabilities for future quantum communication, remote sensing and imaging applications., 17 pages, 26 Figures

The field of quantum information processing offers secure communication protected by the laws of quantum mechanics and is on the verge of finding wider application for information transfer of sensitive data. To overcome the obstacle of inadequate cost-efficiency, extensive research is being done on the many components required for high data throughput using quantum key distribution (QKD). Aiming for an application-oriented solution, we report on the realization of a multichannel QKD system for plug-and-play high-bandwidth secure communication at telecom wavelength. For this purpose, a rack-sized multichannel superconducting nanowire single photon detector (SNSPD) system, as well as a highly parallelized time-correlated single photon counting (TCSPC) unit have been developed and linked to an FPGA-controlled QKD evaluation setup allowing for continuous operation and achieving high secret key rates using a coherent-one-way protocol., 13 pages, 6 figures

With a bifunctional symmetric RAFT agent well-defined polymer structures can be achieved. This paper shows the possibility to synthesize block copolymer systems consisting out of different activated monomers. With the novel bifunctional symmetric RAFT agent water-born polymer systems with a block structure (B-b-A-b-B) can be polymerized. The symmetric RAFT agent is designed to polymerize both more activated monomers (A) and less activated monomers (B). Due to the ability of a controlled radical polymerization of different activated monomers the dispersity of the resulting polymers is broader compared to common RAFT polymerizations. In regard to industrial applications like emulsifiers, stabilizers or viscosity modifiers the broader molecular weight distribution has no impact. Overall, this paper shows the possibility towards new functional polymers with unique properties.

This chapter illustrates the case of the Herero and Nama in German South-West Africa, an exceptionally brutal case of pacification. The Herero, who had initially accepted state authority in the early 1890s, were increasingly confronted with an expanding settler population with which they competed for the same resources. Ensuing violent dispossession and brutal displacement of indigenous groups by settlers, a process only marginally controlled, but approved by the state, resulted in an uprising and fierce resistance by the Herero in 1904. This led to a massive military campaign by the colonial army against the insurgent Herero and (somewhat later) Nama on behalf of the European settlers. “Pacification” was achieved by the almost complete annihilation of the Herero and Nama.

We present waveguide-integrated superconducting nanowire single-photon detectors with high system detection efficiency over extremely broad bandwidth. Exploiting photonic integrated circuit functionalities, we further enable photon number resolution capabilities of up to eight photons.

Zusammenfassung Nach Raphael Lemkin, dem Schopfer des Genozidbegriffs, war Siedlungskolonialismus von Grund auf genozidal. Das Beispiel „Deutsch-Sudwestafrika“ widerlegt diese These insofern, als die tragenden Krafte der Besiedlung sowie die langfristige Politik die indigene Arbeitskraft moglichst zu erhalten suchten. Nichtsdestotrotz war die Koexistenz mit den Indigenen von Grausamkeit und einem eklatanten Gewaltuberschuss gepragt, mit dem sich die herkommliche Genozidtheorie schwertut. Die Begriffe „Kultur der Grausamkeit“ und „eradierende Praktiken“ suchen diesen Uberschuss zu konzeptualisieren und somit einen Beitrag zur Erforschung extremer Gewalt zu leisten. Summary Raphael Lemkin, creator of the concept of genocide, assumed that settler colonialism was inherently genocidal. However, the case of “German Southwest-Africa” contradicts this general assumption in certain respects. As a matter of fact, a closer look reveals that the backbone of colonization and long-term policy sought to sustain indigeno...

Zusammenfassung In den Augen höherer Offiziere aus der Metropole war die »Kaiserliche Schutztruppe in Deutsch-Südwestafrika« militärisch eine Hinterwelt und dem Heimatheer in allen Belangen unterlegen. Die Erfahrung insbesondere jüngerer Offiziere, die sich unter den massiven Truppenverstärkungen im Zuge der Aufstände von 1904 befanden und bei den Feldtruppen ihren Dienst versahen, fiel hingegen ganz anders aus. Nach ihren Berichten erwiesen sich sowohl Offiziere wie auch Mannschaften den aus der Heimat herausgesandten Kräften als deutlich überlegen. Dies hing nicht nur mit ihrer besseren Kenntnis von Land, Gegnern und Kleinkriegführung zusammen. So zeichneten sich die Offiziere dadurch aus, dass sie nicht blind dem »Dogma der Vernichtungsschlacht« anhingen, sondern wussten, dass das Operative nur einen Aspekt neben anderen der Kriegführung darstellt, und legten ein hohes Maß an sozialer Verantwortung »nach unten« an den Tag. Die Selbstständigkeit, zu der die Mannschaften erzogen waren und die freilich auch der Logik der Siedlergesellschaft folgte, nahm sie deutlich gegenüber den »neuen« Verbänden aus und machte sie zu einer Verkörperung des Soldaten, dessen die Schlachtfelder des 20. Jahrhunderts bedurften. Die »alte« Schutztruppe war nicht nur nicht ihrer Zeit hinterher, sondern dieser sogar deutlich voraus.

This paper investigates the influence of accounting standards on systematic earnings understatement. To isolate the effect of reporting regulations from those of other institutional drivers of earnings management, Holthausen (2003) proposes analyzing reporting practices in a country undergoing a transition in accounting standards. We respond to this call by analyzing earnings management practices of large German-listed companies before and after their transitions from German GAAP to IFRS. Specifically, we focus on Big Bath behavior following Chief Financial Officer turnovers between 1999 and 2006. Our findings provide evidence of the effect of accounting standards on the existence of this particular earnings understatement pattern. However, while we detect Big Bath behavior for our sample of German GAAP firms, we find no such indication for those firms reporting under IFRS. Controlling for alternative explanations such as self-selection bias does not change our findings. We conclude that accounting standards seem to have a considerable influence on earnings management behavior, independent of managers’ and auditors’ incentives.

The photophysics of a homopolymer containing pendant phenoxy-benzothiadiazole-bis(thiophene) (OPhBTDT2) moieties, a block copolymer containing both OPhBTDT2 and triphenylamine-based (TPA) pendant units, and a benzothiadiazole model compound, were investigated using steady-state and time-resolved photo-spectroscopic techniques, and quantum mechanical calculations. Electronic excitation of the OPhBTDT2 chromophores leads to rapid intra-molecular charge re-distribution in the lowest unoccupied molecular orbital resulting in substantially increased electron density on the BTD component. In dilute fluid solution, the fluorescence lifetime of the OPhBTDT2 moieties in the block co-polymer was partially quenched due to photo-oxidation of TPA. The triplet excited-state lifetime of the OPhBTDT2 groups in the block co-polymer in solution was unaffected by the TPA moieties signifying that triplet excited-state OPhBTDT2 groups do not oxidize the TPA moieties. In spin-cast films, the OPhBTDT2 singlet and triplet excitons are shorter-lived than the corresponding excited states of the polymers or the OPhBTDT2 model compound in dilute solution, and the lifetimes are essentially independent of the presence of the TPA groups in the block co-polymer. This quenching of OPhBTDT2 exciton lifetimes in the films suggests efficient non-radiative energy migration to low-energy traps, possibly non-emissive OPhBTDT2 molecular aggregates. The complete quenching of fluorescence from OPhBTDT2 in a 1:1 blend of the OPhBTDT2 homoploymer and the electron acceptor [6,6]-phenyl C 61 butyric acid methyl ester (PC 61 BM) is attributed to efficient photo-induced reduction of PC 61 BM by OPhBTDT2 singlet excitons based on evidence for radical ion formation obtained from nanosecond transient absorbance measurements. The decay kinetics of the absorbance by the resulting charge carriers is consistent with a slow, trap-limited bimolecular recombination mechanism, so the low performance of photovoltaic devices produced using the blend is thought to be limited by extensive phase separation and/or low hole mobility.

This review focuses on the approaches to the synthesis of functional polymers for optoelectronic applications that make use of radical polymerization with reversible addition–fragmentation chain transfer (RAFT) polymerization. Optoelectronic applications include hole/electron transport in photovoltaics (OPVs), light emitting diodes (OLEDs and PLEDs), thin-film transistors (TFTs), sensors, light-harvesting and related applications. In this context we consider metallopolymers (polymers that incorporate a metal or possess metal ligating functionality as a pendant group to the backbone, as an end-group or as a connecting group), organic semiconductors (polymers with an organic semiconductor moiety either as a block or as a pendant group), and various surfaces, nanoparticles and quantum dots that are formed by RAFT polymerization or where a RAFT-synthesized polymer forms an integral part of the process or structure.

The synthesis of a series of novel, unsymmetrically substituted benzothiadiazole-containing vinyl monomers and their free radical polymerization with and without the control of a reversible addition−fragmentation chain transfer (RAFT) agent is reported. The resulting polymers with electroactive pendants show tunable absorption and emission spectra depending on their molecular architecture. Using RAFT allows the synthesis of block copolymers using a hole-transporting vinyl-triarylamine as a second monomer. Efficient energy transfer between the two pendants has been detected. Cyclic voltammetry and photoelectron spectroscopy in air measurements have been employed to reveal the location of the HOMO and LUMO of the block copolymers. The block copolymers also influence the morphology of spin-casted films and show rectifying behavior in organic photovoltaic devices.

Whereas most conventional DNA probes are flat disklike aromatic molecules, we explored the possibility of developing quadruplex sensors with nonplanar conformations, in particular, the propeller-shaped tetraphenylethene (TPE) salts with aggregation-induced emission (AIE) characteristics. 1,1,2,2- Tetrakis(4-(2-triethylammonioethoxy)- phenyl)ethene tetrabromide (TPE-1) was found to show a specific affinity to a particular quadruplex structure formed by a human telomeric DNA strand in the presence of K + ions, as indicated by the enhanced and batho- chromically shifted emission of the AIE fluorogen. Steady-state and time- resolved spectral analyses revealed that the specific binding stems from a struc- tural matching between the AIE fluor- ogen and the DNA strand in the fold- ing process. Computational modeling suggests that the AIE molecule docks on the grooves of the quadruplex sur- face with the aid of electrostatic attrac- tion. The binding preference of TPE-1 enables it to serve as a bioprobe for direct monitoring of cation-driven con- formational transitions between the quadruplexes of various conformations, a job unachievable by the traditional G-quadruplex biosensors. Methyl thia- zolyl tetrazolium (MTT) assays reveal that TPE-1 is cytocompatible, posing no toxicity to living cells.

A facile synthetic route to functional hyperbranched polymers is developed. Arylene bipropiolates (HC≡C−CO2−Ar−O2C−C≡CH; 1−4) are readily prepared from a one-step esterification reaction between commercially available propiolic acid and arylene diols. Polycyclotrimerizations of 1−4 proceed regioselectively in reflux dimethylformamide (DMF), giving hyperbranched poly[1,3,5-tri(aroxycarbonyl)phenylene]s (hb-P1−hb-P4) of high molecular weights (Mw up to ∼8.3 × 105) in high yields (up to 82%). The polymers possess perfect 1,3,5-regiostructures and high degrees of branching (DB ∼ 88%). Little weights are lost when the polymers are heated to 390 °C under nitrogen or 380 °C in air. The polymers are highly transparent, allowing almost all light in the entire visible spectral region to transmit through. Thin solid film of hb-P1 shows high refractive indices (RI = 1.6255−1.681) in the wavelength region of 400−1700 nm, extremely high modified Abbe number (νD′ = 1030.7), and very low optical dispersion (D′ = 0.000 97...

The synthesis of functionalized siloles has been a challenge because of the incompatibility of polar functional groups with the reactive intermediates in the conventional protocols for silole synthesis. In this work, a synthetic route for silole functionalization is elaborated, through which a series of functionalized siloles are successfully prepared. Whereas light emissions of traditional luminophores are often quenched by aggregation, most of the functionalized siloles show an exactly opposite phenomenon of aggregation-induced emission (AIE). The siloles are nonemissive when dissolved in their good solvents but become highly luminescent when aggregated in their poor solvents or in the solid state. Manipulation of the aggregation–deaggregation processes of the siloles enables them to play two seemly antagonistic roles and work as both excellent quenchers and efficient emitters. The AIE effect endows the siloles with multifaceted functionalities, including fluorescence quenching, pH sensing, explosive detection, and biological probing. The sensing processes are very sensitive (with detection limit down to 0.1 ppm) and highly selective (with capability of discriminating among different kinds of ions, explosives, proteins, DNAs, and RNAs). The siloles also serve as active layers in the fabrication of electroluminescent devices and as photosensitive films in the generation of fluorescence patterns.

A group of hyperbranched poly(silylenearylene)s are synthesized by homopolycyclotrimerizations of A2-type silylenediynes. The polymers can be readily metallized by complexations of their periphery triple bonds with cobalt octacarbonyls Co2(CO)8. Pyrolysis of these organometallic polymers gives magnetic ceramics in good yields. Analyses by SEM, TEM, XPS, EDX, and XRD demonstrate that the ceramics comprise ferromagnetic Co and paramagnetic Co2Si nanocrystallites wrapped by carboneous shell. The ceramics show high magnetic susceptibilities (M s up to ~50 emu/g) and near-zero coercivity (H c down to ~0.14 kOe), suggesting that they are good soft magnetic materials with low hysteresis loss.

Synthesis of hyperbranched poly(1,2,3-triazole)s (hb-PTAs) has been a challenge: the AB2 monomers were inclined to self-oligomerize, and their Cu(I)-catalyzed click polymerizations failed to yield soluble polymers. We tackled the challenge in this work and succeeded in generating hb-PTAs with regioregularity, processability, and functionality. We took an A2 + B3 approach and used diazides 2 and triyne 3 as monomers, which are free of self-oligomerization concerns. Thermal polymerizations of 2 and 3 produced regiorandom polymers (hb-r-P1) with high molecular weights in high yields. Metal-mediated regioselective polymerizations afforded soluble 1,4- and 1,5-linked polymers (hb-1,4-P1 and hb-1,5-P1), presenting the first examples of regioregular hb-PTAs with macroscopic processability. The reactions were affected by substrate and catalyst: electron-rich alkyne generally slowed down the cycloaddition reaction, while ruthenium catalysts (Cp*Ru(PPh3)2Cl and [Cp*RuCl2]n) exhibited higher substrate tolerance than...

Hyperbranched poly(ferrocenylphenylenes) (hb-PFPs) with high molecular weights were synthesized by the copolycyclotrimerizations of (E,E)-1,1‘-bis[2-(4-ethynylphenyl)vinyl]ferrocene (1) with (E)-1-[2-(4-ethynylphenyl)vinyl]ferrocene (2) catalyzed by TaCl5−Ph4Sn at room temperature in high yields (up to 97%). Effects of reaction conditions, such as monomer and catalyst concentrations, reaction time and molar feed ratio (r1/2), on the copolycyclotrimerization were investigated. Solubility of the copolymer is decreased with an increase in its content of diyne component (N1/N2). The hb-PFPs were characterized by IR, NMR, UV, CV and TGA analyses. The copolymers are redox active, whose oxidation potentials are decreased with an increase in N1/N2. They are thermally stable, losing ∼5% of weights when heated to 384−400 °C and retaining ∼70% of weights when pyrolyzed at 1200 °C. The complexation with cobalt carbonyl further metallizes the hb-PFPs and the pyrolytic ceramization of the cobalt−polymer complexes yield...

AB n -type monomers have been widely used for the synthesis of hyperbranched polymers. These monomers, however, suffer from the problems associated with the tendency of their mutually reactive A and B functional groups toward self-oligomerization. We have explored the possibility of synthesizing hyperbranched polymers using A n -type monomers, which are stable and easy to prepare and handle, with some being even commercially available. In particular, we have tried to open new synthetic routes to hyperbranched polymers using diynes and triynes as monomers. We have developed metallic [TaBr 5 , Cp ∗ Ru(PPh 3 ) 2 Cl, etc.] and nonmetallic catalysts (piperidine, DMF, etc.) for polycyclotrimerization, polycycloaddition and polycoupling of the acetylenic monomers. We have synthesized a variety of new hyperbranched polymers including polyarylenes, polytriazoles and polydiynes with high molecular weights and excellent solubility in high yields. The polymers exhibit an array of functional properties such as sensitive photonic response, high light refractivity, large optical nonlinearity, high thermal stability, strong optical limiting power and unusual aggregation-enhanced light emission. Utilizing these unique properties, we succeeded in generating fluorescent images, honeycomb patterns, polymer nanotubes, ferromagnetic ceramics, and nanoparticle catalysts.

A group of hyperbranched poly(silylenephenylenes) (hb-PSPs) were synthesized in high yields (up to 100%) by TaBr5-catalyzed polycyclotrimerization of A2-type monomers of silylenediynes [HC⋮C−C6H4−Si(CnH2n+1)2−C6H4−C⋮CH, n = 2, 4, 6]. The hb-PSPs are completely soluble in common organic solvents such as chloroform, toluene, and THF. Spectroscopic and modeling studies confirmed that the polymers had formed via a [2 + 2 + 2] cyclotrimerization mechanism. Analysis of the triple-bond conversion processes led to the establishment of a relationship between the degree of branching and the fraction of dendritic unit. Computational simulation shed light on the real topological structures of the hb-PSPs. The polymers lost little weights when heated up to 480 °C and carbonize in high yields (up to 71%) after pyrolysis at 800 °C. The hb-PSPs possess a unique σ−π conjugated electronic structure and emit strong violet-blue light upon photoexcitation. The triple bonds on the peripheries allowed the thin films of the poly...

A hyperbranched poly(aroylarylene) containing triphenylamine (TPA) moiety (hb-P1) is synthesized by metal-free polycyclotrimerization of N,N-bis(4-ethynylcarbonylphenyl)aniline (1) in a high yield (86%) with a perfect 1,3,5-regioregularity. The polymer is soluble in common organic solvents such as THF and chloroform and is thermally stable, losing 5% of its weight when heated to a temperature as high as ∼450 °C. The polymer is fluorescent and solvatochromic, whose emission color changes from ∼455 nm (blue) in toluene to 549 nm (yellow) in DMF. The polymer exhibits a large two-photon absorption cross-section due to the intramolecular charge transfer between its electron-donating TPA and electron-withdrawing 1,3,5-tricarbonylbenzene groups.