152 research outputs found
Der platonische Nietzsche
Mit der Behauptung, dass seine eigene Philosophie als »umgedrehter Platonismus« verstanden werden soll, stellt Nietzsche seine Beziehung zum platonischen System dar. Dieses Forschungsprojekt sucht nach einer neuen Variation dieser Darstellung, um die philosophischen Analogien beider Autoren aufzuspüren. Das erste Kapitel beschäftigt sich mit einer Erläuterung des Begriffes „umgedrehter Platonismus“, womit die Differenz zwischen diesen beiden Systemen definiert wird. Diese Diskrepanz ist spürbar in vier verschiedene Bereichen: metaphysisch, axiologisch, gnoseologisch und ästhetisch. Das zweite Kapitel behandelt die Rolle des Apollinischen und des Dionysischen in der nietzscheschen Theorie. Die beiden Konzepte werden mit dem des platonischen Eros verglichen, da diese es dem Menschen ermöglichen, die sinnliche Welt zu verlassen und eine Ur-Realität kennenzulernen. Das dritte Kapitel analysiert die Verurteilung der Kunst in Platon’s „Staat“. Der griechische Philosoph strebt die wahre Kenntnis an und verbindet seine ästhetischen Überlegungen mit der Idee der Wahrheit. Nietzsche bearbeitet diese Verbindung zwischen Ästhetik und Erkenntnistheorie unter dem Begriff »amor fati«. Das vierte Kapitel ist der Physiologie der Liebe gewidmet. Nietzsche verwandelt der Erkenntnisprozess in eine leidenschaftliche Liebe. Die Erkenntnis nimmt die Form einer Passion an und kristallisiert sich allmählich und nach einem langen Prozess mit Höhen und Tiefen in »amor fati«. »Amor fati« schafft eine Ästhetisierung der Erkenntnis und Epistemologiesierung der Ästhetik. Somit liegt Nietzsches Erkenntnistheorie parallel zu jener Platons.By claiming that his philosophy should be understood as “inverted Platonism” Nietzsche defined his relationship to the Platonic system. This research project aims to articulate a new understanding of this relationship by analyzing philosophical similarities between the two authors'' respective philosophies. The first chapter is dedicated to the explanation of the term “inverted Platonism” and articulates the differences between Plato''s and Nietzsche''s systems. These discrepancies are manifested in four main areas: the metaphysical, the axiological, the gnosiological and the aesthetic. The second chapter deals with the roles of the Apollonian and the Dionysian in Nietzschean theory. Both concepts are compared with the Platonic Eros, as they invite man to abandon the sensual world and instead to commune with the very origin of reality. The third chapter analyzes Plato´s denunciation of art in “The Republic”. The Greek philosopher seeks true knowledge and connects his aesthetic concerns with the idea of Truth. Nietzsche refers to the cynosure between aesthetics and cognitive theory as “amor fati”. The fourth chapter is dedicated to the physiology of love. Nietzsche transforms the cognitive process into a passionate love. Cognition assumes the shape of passion, slowly crystallizing over time, with many twists and turns, into “amor fati”. “Amor fati” aestheticizes cognition and epistemologizes aesthetics. Therefore Nietzsche''s cognitive theory is actually equivalent to that of Plato
Formation and Oxidation State of CeO<sub>2</sub><sub>-</sub><i><sub>x</sub></i> Nanotubes
Well-crystalline CeO2-x nanotubes are synthesized via a mild hydrothermal reaction route using cerium nitrate and ammonium hydroxide as reactants. The CeO2-x nanotubes have the same structure as the bulk CeO2 but larger lattice parameter. The measurement of the ratio of M5/M4 edge shows the valence reduction of cerium ions for the CeO2-x nanotubes
Regio- and Stereoselective Synthesis of 2‑Amino-dienes via Decarboxylative Amination of 4‑(Ethoxycarbonyl)-2,3-allenols by TsNCO
A metal-free decarboxylative amination
of 4-(ethoxycarbonyl)-2,3-allenols
by TsNCO via base-induced aza-Michael addition/elimination has been
developed. A variety of substituted N-tosyl 1,3-dien-2-yl
amines were obtained in good yields and excellent regio- and stereoselectivity.
Moreover, this transformation could be applied in preparation of 2-amino-trienes
Media 1: Dual-wavelength orthogonally polarized radiation generated by a tungsten thermal source
Originally published in Optics Express on 18 November 2013 (oe-21-23-28570
Spectroscopic probe to contribution of physicochemical transformations in the toxicity of aged ZnO NPs to <i>Chlorella vulgaris</i>: new insight into the variation of toxicity of ZnO NPs under aging process
<p>Zinc oxide nanoparticles (ZnO NPs) are one of the most abundantly applied nanomaterials in nanotechnology-based industries and they may cause unexpected environmental and health risks with their physicochemical transformations in the environment. Currently, there is still a lack of the in-depth understanding of the toxicity of aged ZnO NPs to aquatic organisms, particularly demanding quantitative analysis of the physicochemical transformations to distinguish their contributions in the toxicity assessment. For this purpose, therefore, we initiated the study of the toxicity of aged ZnO NPs to the model aquatic microalga, i.e. <i>Chlorella vulgaris</i>, and with the aid of spectroscopic tools for characterization and quantification of the physicochemical transformations, we scrutinized the toxicity variations for ZnO NPs with different aging times. As a result, we found that the toxicity altered in an abnormal manner with the aging time, i.e. the toxicity of aged ZnO NPs for 30 days showed the higher toxicity to the green alga than the fresh ZnO NPs or the ZnO NPs aged for longer time (e.g. 120 and 210 days). Through spectroscopic tools such as XRD, FTIR and Raman spectroscopy, we made both the qualitative and quantitative assessments of the physicochemical changes of the ZnO NPs, and confirmed that in the early stage, the toxicity mainly stemmed from the release of zinc ions, but with longer aging time, the neoformation of the nanoparticles played the critical role, leading to the overall reduced toxicity due to the less toxic hydrozincite and zinc hydroxide in the transformed compounds.</p
Regio- and Stereoselective Synthesis of 2‑Amino-dienes via Decarboxylative Amination of 4‑(Ethoxycarbonyl)-2,3-allenols by TsNCO
A metal-free decarboxylative amination
of 4-(ethoxycarbonyl)-2,3-allenols
by TsNCO via base-induced aza-Michael addition/elimination has been
developed. A variety of substituted <i>N</i>-tosyl 1,3-dien-2-yl
amines were obtained in good yields and excellent regio- and stereoselectivity.
Moreover, this transformation could be applied in preparation of 2-amino-trienes
Rapid Synthesis of Stable and Functional Conjugates of DNA/Gold Nanoparticles Mediated by Tween 80
Gold nanoparticles conjugated with DNA represent an attractive and alternative platform for broad applications in biosensors, medical diagnostic, and biological analysis. However, current methods to conjugate DNA to gold nanoparticles are time-consuming. In this study, we report a novel approach to rapidly conjugate DNA to gold nanoparticles (AuNPs) to form functional DNA/AuNPs in 2–3 h using Tween 80 as protective agent. With a fluorescence-based technique, we determine that the DNA density on the surface of AuNPs achieves about ∼60 strands per particles, which is comparable to the loading density in the current methods. Moreover, the DNA/AuNPs synthesized by our approach exhibit an excellent stability as a function of temperature, pH, and freeze–thaw cycle, and the functionality of DNA/AuNPs conjugates is also verified. The work presented here has important implications to develop the fast and reproducible synthesis of stable DNA-functionalized gold nanoparticles
Comparison of Photoluminescence Quantum Yield of Single Gold Nanobipyramids and Gold Nanorods
Fluorescent gold nanoparticles with high quantum yield are highly desirable for optical imaging in the fields of biology and materials science. We investigate the one-photon photoluminescence (PL) properties of individual gold nanobipyramids (GNBs) and find they are analogous to those of the extensively studied gold nanorods (GNRs). By combining PL and atomic force microscopy (AFM) measurements with discrete dipole approximation (DDA) simulations, we obtain the PL quantum yield of single GNRs and GNBs. Compared to GNRs in the similar surface plasmon resonance range, the PL quantum yield of GNBs is found to be doubled. The stronger field intensity around GNBs can explain their higher PL quantum yields. Our research would provide deeper understanding of the mechanism of PL from gold nanoparticles as well as be beneficial for finding out optical imaging labels with high contrast
LiCoO<sub>2</sub> Concaved Cuboctahedrons from Symmetry-Controlled Topological Reactions
Morphology control of functional materials is generally performed by controlling the growth rates on selected orientations or faces. Here, we control particle morphology by “crystal templating”: by choosing appropriate precursor crystals and reaction conditions, we demonstrate that a material with rhombohedral symmetrynamely the layered, positive electrode material, LiCoO2can grow to form a quadruple-twinned crystal with overall cubic symmetry. The twinned crystals show an unusual, concaved-cuboctahedron morphology, with uniform particle sizes of 0.5−2 μm. On the basis of a range of synthetic and analytical experiments, including solid-state NMR, X-ray powder diffraction analysis and HRTEM, we propose that these twinned crystals form via selective dissolution and an ion-exchange reaction accompanied by oxidation of a parent crystal of CoO, a material with cubic symmetry. This template crystal serves to nucleate the growth of four LiCoO2 twin crystals and to convert a highly anisotropic, layered material into a pseudo-3-dimensional, isotropic material
Molecular Engineered Carbon-Based Sensor for Ultrafast and Specific Detection of Neurotransmitters
In the quest for designing affordable
diagnostic devices with high
performance, precisely functionalized carbon-based materials with
high accuracy and selectivity are required. Every material has its
own unique ability to interact with the analyte, and its performance
can be enhanced by probing the interaction mechanism. Herein, p-aminophenol (PAP)-functionalized reduced graphene oxide
(rGO) nanoscale material is developed by a one-step synthetic route
as an all-organic-based sensor. As the PAP molecules are precisely
covalently interacted with the rGO at the basal plane and form a wrinkled-paper-like
structure, the functionalized material exhibits an outstanding sensing
ability (7.5 nM neurotransmitter dopamine (DA) at a wide linear range,
0.01–100 μM) with fast electrical transduction (<3
s) and good recyclability (∼10 cycles) in a real sample. Combining
various analytical and density functional theory (DFT) calculation
methods, physicochemical properties and the interaction mechanism
of analyte–materials transduction are discussed exclusively.
Besides, the potential application of the well-dispersed rGO-PAP gravure
ink in flexible-printed electronics fields is explored. This study
not only provides new insights into the surface/interface chemistry
and working principle of this unique anchoring of PAP on rGO but also
offers a new pathway for developing other forms of metal-free/organic
functionalized biosensors with high efficiency
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