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Papers by Hans-Eckhardt Schaefer

Research paper thumbnail of Music-Evoked Emotions—Current Studies

Frontiers in Neuroscience, Nov 24, 2017

The present study is focused on a review of the current state of investigating music-evoked emoti... more The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields.

Research paper thumbnail of Vacancy formation in iron investigated by positron annihilation in thermal equilibrium

Scripta Metallurgica, 1977

Research paper thumbnail of Limited Dispersal and Significant Fine - Scale Genetic Structure in a Tropical Montane Parrot Species

PloS one, 2016

Tropical montane ecosystems are biodiversity hotspots harbouring many endemics that are confined ... more Tropical montane ecosystems are biodiversity hotspots harbouring many endemics that are confined to specific habitat types within narrow altitudinal ranges. While deforestation put these ecosystems under threat, we still lack knowledge about how heterogeneous environments like the montane tropics promote population connectivity and persistence. We investigated the fine-scale genetic structure of the two largest subpopulations of the endangered El Oro parakeet (Pyrrhura orcesi) endemic to the Ecuadorian Andes. Specifically, we assessed the genetic divergence between three sites separated by small geographic distances but characterized by a heterogeneous habitat structure. Although geographical distances between sites are small (3-17 km), we found genetic differentiation between all sites. Even though dispersal capacity is generally high in parrots, our findings indicate that dispersal is limited even on this small geographic scale. Individual genotype assignment revealed similar gene...

Research paper thumbnail of The relative importance of color signaling for plant generalization in pollination networks

Research paper thumbnail of Defects in low‐temperature electron‐irradiatedp‐type silicon

Journal of Applied Physics, 1992

Defects in monocrystalline silicon have been studied in the past, in particular, defects induced ... more Defects in monocrystalline silicon have been studied in the past, in particular, defects induced by room-temperature electron and proton irradiations on both n-andp-type materials, and most of the corresponding defects have been tentatively identified. However, there are still several questions which remain to be answered such as the nature and behavior of the defects introduced in the range 4-300 K. In this work Czochralski-grown p-type material has been irradiated at three different temperatures (90, 200, and 300 K) and characterized by deep-level transient spectroscopy (DLTS) and lifetime measurements. The data show that the defects created after irradiations at 90 and 200 K are different from those reported in the literature for irradiations at 4,77, and 300 K, showing that three annealing steps exist between 4 and 300 K. These defects are characterized and a tentative identification of them is made. Finally, an attempt to detect the defects responsible for the lifetime, i.e., the recombination centers, not observed by DLTS, using spin-dependent recombination is described.

Research paper thumbnail of Vacancies selectively induced and specifically detected on the two sublattices of the intermetallic compoundMoSi2

Physical Review B, 2002

In the present study vacancies were selectively induced on the Si or predominantly on the Mo subl... more In the present study vacancies were selectively induced on the Si or predominantly on the Mo sublattices of MoSi 2 single crystals by low-temperature irradiation with electrons of low or high energies. These vacancies were specifically detected by employing two-detector Doppler broadening measurements of the positronelectron annihilation ␥ quanta in addition to positron lifetime studies. Positron lifetime studies show that two kinds of vacancies on either the Si or the Mo sublattices were induced in MoSi 2 by 0.5-or 3-MeV electron irradiation. After 0.5-MeV electron irradiation Doppler broadening spectra characteristic for Mo are detected, which shows that the vacancies with the 139 ps positron lifetime are located on the Si sublattice. After 3-MeV electron irradiation, only Si atoms were detected to surround the vacancy with the 156 ps positron lifetime, which demonstrates that in this case positrons are predominantly trapped by vacancies on the Mo sublattice. In the present experiment the selective introduction of vacancies and the detection of their location on different sublattices have proven to be a promising technique for specifically studying atomic defects in solids with a complex structure.

Research paper thumbnail of Encapsulating segment-like antimony nanorod in hollow carbon tube as long-lifespan, high-rate anodes for rechargeable K-ion batteries

Nano Research, 2019

K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of lo... more K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of low-cost and abundant resource of potassium. To develop advanced electrode materials for accommodating the large size and high activity of potassium ion is of great interests. Herein, a segment-like antimony (Sb) nanorod encapsulated in hollow carbon tube electrode material (Sb@HCT) was prepared. Beneficial from the virtue of abundant nitrogen doping in carbon tube, one-dimensional and hollow structure advantages, Sb@HCT exhibits excellent potassium storage properties: in the case of potassium bis(fluorosulfonyl)imide (KFSI) electrolyte, Sb@HCT displays a reversible capacity of up to 453.4 mAh•g −1 at a current density of 0.5 A•g −1 and good rate performance (a capacity of 211.5 mAh•g −1 could be achieved at an ultrahigh rate of 5 A•g −1). Additionally, Sb@HCT demonstrates excellent long-cycle stability at a current density of 2 A•g −1 over 120 cycles. Meanwhile, electrolyte optimization is an effective strategy for greatly improving electrochemical performance. Through ex-situ characterizations, we disclosed the potassiation of Sb anode is quite reversible and undergoes multistep processes, combining solid solution reaction and two-phase reaction.

Research paper thumbnail of Nanoscience

Research paper thumbnail of Music-Evoked Emotions—Current Studies

Frontiers in Neuroscience, 2017

The present study is focused on a review of the current state of investigating music-evoked emoti... more The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields.

Research paper thumbnail of Atomistic modeling of the ordering of disordered nanocrystalline FeAl and NiAl

Research paper thumbnail of Investigation of Thermal Equilibrium Vacancies in Metals by Positron Annihilation

Physica Status Solidi (a), 1987

... formation in the noble metals by such techniques as differential thermal expansion in the vic... more ... formation in the noble metals by such techniques as differential thermal expansion in the vicinity of T, [2, 341, quenching (see 131) as well as positron annihilation using either momentum parameters or mean lifetime measurements. Positron lifetime spectroscopy has been ...

Research paper thumbnail of Vacancy formation in indium investigated by positron lifetime spectroscopy

Journal of Physics F: Metal Physics, 1985

ABSTRACT

Research paper thumbnail of NanochemistryNanochemistry – From Supramolecular Chemistrysupramolecular chemistry to Chemistry on the Nanoscalechemistry on the nanoscale , Catalysiscatalysis , Renewable Energyrenewable energy , Batteriesbatteries , and Environmental Protectionenvironmental protection

Nanoscience, 2010

Chemistry plays an important role in the synthesis of nanostructures (see Chap. 3 and [10.1]). In... more Chemistry plays an important role in the synthesis of nanostructures (see Chap. 3 and [10.1]). In the present section, the main features of supramolecular chemistry and of inorganic hollow clusters will be outlined with a subsequent discussion of chemical reactions on the nanoscale and catalysis. Furthermore, nanochemistry and nanoscience appear to be of importance for future renewable energy production, battery development, and environmental protection.

Research paper thumbnail of Thermal Vacancy Formation in Ni3Al and γ-TiAl Compounds Studied by Positron Lifetime and Nearest-Neighbour Bond Models

Materials Science Forum, 1995

ABSTRACT

Research paper thumbnail of Vacancy Formation in Molybdenum and Tungsten Investigated by Positron Lifetime Measurements

Materials Science Forum, 1987

Research paper thumbnail of Carbon NanostructuresCarbon nanostructures – Tubes, Graphenegraphene , Fullerenesfullerenes , Wave-Particle Dualitywave-particle duality

Nanoscience, 2010

ABSTRACT

Research paper thumbnail of Erratum: Thermal formation of vacancies in Fe 3 Si

Physical Review B, 1996

ABSTRACT

Research paper thumbnail of Nanotechnology for ComputersNanotechnology for computers , Memoriesmemories , and Hard Diskshard disks

Nanoscience, 2010

ABSTRACT

Research paper thumbnail of Structure and diffusional properties of nanocrystalline Pd

Philosophical Magazine B, 1997

Nanocrystalline (nc) solids are characterized by nanometre crystallite size and a high number of ... more Nanocrystalline (nc) solids are characterized by nanometre crystallite size and a high number of interfaces. In the present paper we report structural and diffusion studies on high purity nanocrystalline Pd (nc-Pd) that was prepared either by cluster compaction to full density or by severe plastic deformation. The size distribution of atomic free volumes in the interfaces studied by positron lifetime

Research paper thumbnail of Atomic defects in hexagonal tungsten carbide studied by positron annihilation

Physical Review B, 2000

Vacancies on the two sublattices of hexagonal tungsten carbide were identified by means of positr... more Vacancies on the two sublattices of hexagonal tungsten carbide were identified by means of positron lifetime studies after irradiation with electron of various energies. In the as-prepared state two predominant positron lifetime components occur indicating positron annihilation in the free state with a lifetime f ϭ124Ϯ10 ps according to the simple trapping model and positron trapping and annihilation in metal vacancies (V W ϭ175 Ϯ20 ps͒ of low concentration. By means of low-energy electron irradiation at 1 MeV with an electron dose of 1.8ϫ10 23 m Ϫ2 exclusively carbon vacancies are introduced giving rise to saturation trapping and annihilation of positrons at carbon vacancies with a low lifetime of V C ϭ136Ϯ3 ps. The isochronal annealing of irradiation induced vacancies reveals two annealing stages at 800 and 1200 K, which are ascribed to the annealing of carbon vacancies and the dissolving of small carbon vacancy clusters.

Research paper thumbnail of Music-Evoked Emotions—Current Studies

Frontiers in Neuroscience, Nov 24, 2017

The present study is focused on a review of the current state of investigating music-evoked emoti... more The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields.

Research paper thumbnail of Vacancy formation in iron investigated by positron annihilation in thermal equilibrium

Scripta Metallurgica, 1977

Research paper thumbnail of Limited Dispersal and Significant Fine - Scale Genetic Structure in a Tropical Montane Parrot Species

PloS one, 2016

Tropical montane ecosystems are biodiversity hotspots harbouring many endemics that are confined ... more Tropical montane ecosystems are biodiversity hotspots harbouring many endemics that are confined to specific habitat types within narrow altitudinal ranges. While deforestation put these ecosystems under threat, we still lack knowledge about how heterogeneous environments like the montane tropics promote population connectivity and persistence. We investigated the fine-scale genetic structure of the two largest subpopulations of the endangered El Oro parakeet (Pyrrhura orcesi) endemic to the Ecuadorian Andes. Specifically, we assessed the genetic divergence between three sites separated by small geographic distances but characterized by a heterogeneous habitat structure. Although geographical distances between sites are small (3-17 km), we found genetic differentiation between all sites. Even though dispersal capacity is generally high in parrots, our findings indicate that dispersal is limited even on this small geographic scale. Individual genotype assignment revealed similar gene...

Research paper thumbnail of The relative importance of color signaling for plant generalization in pollination networks

Research paper thumbnail of Defects in low‐temperature electron‐irradiatedp‐type silicon

Journal of Applied Physics, 1992

Defects in monocrystalline silicon have been studied in the past, in particular, defects induced ... more Defects in monocrystalline silicon have been studied in the past, in particular, defects induced by room-temperature electron and proton irradiations on both n-andp-type materials, and most of the corresponding defects have been tentatively identified. However, there are still several questions which remain to be answered such as the nature and behavior of the defects introduced in the range 4-300 K. In this work Czochralski-grown p-type material has been irradiated at three different temperatures (90, 200, and 300 K) and characterized by deep-level transient spectroscopy (DLTS) and lifetime measurements. The data show that the defects created after irradiations at 90 and 200 K are different from those reported in the literature for irradiations at 4,77, and 300 K, showing that three annealing steps exist between 4 and 300 K. These defects are characterized and a tentative identification of them is made. Finally, an attempt to detect the defects responsible for the lifetime, i.e., the recombination centers, not observed by DLTS, using spin-dependent recombination is described.

Research paper thumbnail of Vacancies selectively induced and specifically detected on the two sublattices of the intermetallic compoundMoSi2

Physical Review B, 2002

In the present study vacancies were selectively induced on the Si or predominantly on the Mo subl... more In the present study vacancies were selectively induced on the Si or predominantly on the Mo sublattices of MoSi 2 single crystals by low-temperature irradiation with electrons of low or high energies. These vacancies were specifically detected by employing two-detector Doppler broadening measurements of the positronelectron annihilation ␥ quanta in addition to positron lifetime studies. Positron lifetime studies show that two kinds of vacancies on either the Si or the Mo sublattices were induced in MoSi 2 by 0.5-or 3-MeV electron irradiation. After 0.5-MeV electron irradiation Doppler broadening spectra characteristic for Mo are detected, which shows that the vacancies with the 139 ps positron lifetime are located on the Si sublattice. After 3-MeV electron irradiation, only Si atoms were detected to surround the vacancy with the 156 ps positron lifetime, which demonstrates that in this case positrons are predominantly trapped by vacancies on the Mo sublattice. In the present experiment the selective introduction of vacancies and the detection of their location on different sublattices have proven to be a promising technique for specifically studying atomic defects in solids with a complex structure.

Research paper thumbnail of Encapsulating segment-like antimony nanorod in hollow carbon tube as long-lifespan, high-rate anodes for rechargeable K-ion batteries

Nano Research, 2019

K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of lo... more K-ion battery (KIB) is a new-type energy storage device that possesses potential advantages of low-cost and abundant resource of potassium. To develop advanced electrode materials for accommodating the large size and high activity of potassium ion is of great interests. Herein, a segment-like antimony (Sb) nanorod encapsulated in hollow carbon tube electrode material (Sb@HCT) was prepared. Beneficial from the virtue of abundant nitrogen doping in carbon tube, one-dimensional and hollow structure advantages, Sb@HCT exhibits excellent potassium storage properties: in the case of potassium bis(fluorosulfonyl)imide (KFSI) electrolyte, Sb@HCT displays a reversible capacity of up to 453.4 mAh•g −1 at a current density of 0.5 A•g −1 and good rate performance (a capacity of 211.5 mAh•g −1 could be achieved at an ultrahigh rate of 5 A•g −1). Additionally, Sb@HCT demonstrates excellent long-cycle stability at a current density of 2 A•g −1 over 120 cycles. Meanwhile, electrolyte optimization is an effective strategy for greatly improving electrochemical performance. Through ex-situ characterizations, we disclosed the potassiation of Sb anode is quite reversible and undergoes multistep processes, combining solid solution reaction and two-phase reaction.

Research paper thumbnail of Nanoscience

Research paper thumbnail of Music-Evoked Emotions—Current Studies

Frontiers in Neuroscience, 2017

The present study is focused on a review of the current state of investigating music-evoked emoti... more The present study is focused on a review of the current state of investigating music-evoked emotions experimentally, theoretically and with respect to their therapeutic potentials. After a concise historical overview and a schematic of the hearing mechanisms, experimental studies on music listeners and on music performers are discussed, starting with the presentation of characteristic musical stimuli and the basic features of tomographic imaging of emotional activation in the brain, such as functional magnetic resonance imaging (fMRI) and positron emission tomography (PET), which offer high spatial resolution in the millimeter range. The progress in correlating activation imaging in the brain to the psychological understanding of music-evoked emotion is demonstrated and some prospects for future research are outlined. Research in psychoneuroendocrinology and molecular markers is reviewed in the context of music-evoked emotions and the results indicate that the research in this area should be intensified. An assessment of studies involving measuring techniques with high temporal resolution down to the 10 ms range, as, e.g., electroencephalography (EEG), event-related brain potentials (ERP), magnetoencephalography (MEG), skin conductance response (SCR), finger temperature, and goose bump development (piloerection) can yield information on the dynamics and kinetics of emotion. Genetic investigations reviewed suggest the heredity transmission of a predilection for music. Theoretical approaches to musical emotion are directed to a unified model for experimental neurological evidence and aesthetic judgment. Finally, the reports on musical therapy are briefly outlined. The study concludes with an outlook on emerging technologies and future research fields.

Research paper thumbnail of Atomistic modeling of the ordering of disordered nanocrystalline FeAl and NiAl

Research paper thumbnail of Investigation of Thermal Equilibrium Vacancies in Metals by Positron Annihilation

Physica Status Solidi (a), 1987

... formation in the noble metals by such techniques as differential thermal expansion in the vic... more ... formation in the noble metals by such techniques as differential thermal expansion in the vicinity of T, [2, 341, quenching (see 131) as well as positron annihilation using either momentum parameters or mean lifetime measurements. Positron lifetime spectroscopy has been ...

Research paper thumbnail of Vacancy formation in indium investigated by positron lifetime spectroscopy

Journal of Physics F: Metal Physics, 1985

ABSTRACT

Research paper thumbnail of NanochemistryNanochemistry – From Supramolecular Chemistrysupramolecular chemistry to Chemistry on the Nanoscalechemistry on the nanoscale , Catalysiscatalysis , Renewable Energyrenewable energy , Batteriesbatteries , and Environmental Protectionenvironmental protection

Nanoscience, 2010

Chemistry plays an important role in the synthesis of nanostructures (see Chap. 3 and [10.1]). In... more Chemistry plays an important role in the synthesis of nanostructures (see Chap. 3 and [10.1]). In the present section, the main features of supramolecular chemistry and of inorganic hollow clusters will be outlined with a subsequent discussion of chemical reactions on the nanoscale and catalysis. Furthermore, nanochemistry and nanoscience appear to be of importance for future renewable energy production, battery development, and environmental protection.

Research paper thumbnail of Thermal Vacancy Formation in Ni3Al and γ-TiAl Compounds Studied by Positron Lifetime and Nearest-Neighbour Bond Models

Materials Science Forum, 1995

ABSTRACT

Research paper thumbnail of Vacancy Formation in Molybdenum and Tungsten Investigated by Positron Lifetime Measurements

Materials Science Forum, 1987

Research paper thumbnail of Carbon NanostructuresCarbon nanostructures – Tubes, Graphenegraphene , Fullerenesfullerenes , Wave-Particle Dualitywave-particle duality

Nanoscience, 2010

ABSTRACT

Research paper thumbnail of Erratum: Thermal formation of vacancies in Fe 3 Si

Physical Review B, 1996

ABSTRACT

Research paper thumbnail of Nanotechnology for ComputersNanotechnology for computers , Memoriesmemories , and Hard Diskshard disks

Nanoscience, 2010

ABSTRACT

Research paper thumbnail of Structure and diffusional properties of nanocrystalline Pd

Philosophical Magazine B, 1997

Nanocrystalline (nc) solids are characterized by nanometre crystallite size and a high number of ... more Nanocrystalline (nc) solids are characterized by nanometre crystallite size and a high number of interfaces. In the present paper we report structural and diffusion studies on high purity nanocrystalline Pd (nc-Pd) that was prepared either by cluster compaction to full density or by severe plastic deformation. The size distribution of atomic free volumes in the interfaces studied by positron lifetime

Research paper thumbnail of Atomic defects in hexagonal tungsten carbide studied by positron annihilation

Physical Review B, 2000

Vacancies on the two sublattices of hexagonal tungsten carbide were identified by means of positr... more Vacancies on the two sublattices of hexagonal tungsten carbide were identified by means of positron lifetime studies after irradiation with electron of various energies. In the as-prepared state two predominant positron lifetime components occur indicating positron annihilation in the free state with a lifetime f ϭ124Ϯ10 ps according to the simple trapping model and positron trapping and annihilation in metal vacancies (V W ϭ175 Ϯ20 ps͒ of low concentration. By means of low-energy electron irradiation at 1 MeV with an electron dose of 1.8ϫ10 23 m Ϫ2 exclusively carbon vacancies are introduced giving rise to saturation trapping and annihilation of positrons at carbon vacancies with a low lifetime of V C ϭ136Ϯ3 ps. The isochronal annealing of irradiation induced vacancies reveals two annealing stages at 800 and 1200 K, which are ascribed to the annealing of carbon vacancies and the dissolving of small carbon vacancy clusters.