Mechanical properties of freely suspended semiconducting graphene-like layers based on MoS2

We fabricate freely suspended nanosheets of molybdenum disulphide (MoS₂) which are characterized by quantitative optical microscopy and high-resolution friction force microscopy. We study the elastic deformation of freely suspended nanosheets of MoS₂ using an atomic force microscope. The Young''s modulus and the initial pre-tension of the nanosheets are determined by performing a nanoscopic version of a bending test experiment. MoS₂ sheets show high elasticity and an extremely high Young''s modulus (0.30 TPa, 50% larger than steel). These results make them a potential alternative to graphene in applications requiring flexible semiconductor materials.PACS, 73.61.Le, other inorganic semiconductors, 68.65.Ac, multilayers, 62.20.de, elastic moduli, 81.40.Jj, elasticity and anelasticity, stress-strain relations.     

MPEG Surround

MPEG's most recent effort to progress the state of the art is the MPEG Surround work item. It provides an efficient method for coding multichannel sound via the transmission of a compressed stereophonic (or even monophonic) audio program plus a low-rate side-information channel. Benefits of this approach include backward compatibility with pervasive stereo playback systems while permitting next-generation players to reconstruct high-quality multichannel sound.     

Damage production in GaAs during MeV ion implantation

The influence of the nuclear and electronic energy loss on the damage production in GaAs has been studied by Se⁺ ion implantation at T_I = 293 K with energies ranging from 2 MeV up to 20 MeV. The ion dose was varied between 5 × 10¹² /cm² and 1 × 10¹⁵ /cm². The damage production was investigated using RBS in channeling regime. Temperature and energy dependent backscattering measurements and TEM investigations were performed to study the kind of defects in more detail. The resulting defect profiles are compared with the depth distribution of the nuclear and electronic energy loss which were simulated by TRIM 87. The results show that the remaining defect concentration strongly decreases with increasing implantation energy even if the same energy density is deposited into nuclear processes. We suppose, that the electronic energy loss increases the defect transformation and annealing during implantation at T_I = 293 K. The defects in the samples implanted with energies greater than 5 MeV are characterized as point defects, point defect clusters and small dislocation loops; the kind of defects are the same over the whole implantation depth and the existence of amorphous zones can be widely excluded.     

Effect of the protein-free calf-blood-extract (Solcoseryl) on the excretion of estrogens in chronic placental insufficiency

In a double blind study the action of Solcoseryl was tested in 31 patients during late pregnancy with chronic placental insufficiency. Under treatment with Solcoseryl a significant increase in urinary estrogen excretion occurred in relation to the placebo-group.     

The effects of the number of links and navigation support on cognitive load and learning with hypertext: The mediating role of reading order

Problems in learning with hypertext systems have been claimed to be caused by high levels of disorientation and cognitive load. This was recognized by DeStefano and LeFevre [DeStefano, D., & LeFevre, J. -A., (2007). Cognitive load in hypertext reading: A review. Computers in Human Behavior, 23(3), 1616–1641.] who predicted an increase of cognitive load and impairment of learning for hypertexts with a higher number of links per page. From a practical perspective, several navigation support techniques, such as providing link suggestions, have been proposed for guiding learners and reducing cognitive overload. In an experiment, we tested DeStefano and LeFevre’s predictions as well as the usefulness of link suggestions. Participants used different versions of a hypertext, either with 3-links or 8-links per page, presenting link suggestions or not. We tested their cognitive load and learning outcomes. Results showed that there was a benefit of using link suggestions for learning, but no effect of number of links on learning was found. Moreover, the effects of our manipulations on cognitive load were mediated by the reading order that participants selected. Implications for research and the design of navigation support systems are discussed.     

Nonmonotonic reasoning with multiple belief sets

In complex reasoning tasks it is often the case that there is no single, correct set of conclusions given some initial information. Instead, there may be several such conclusion sets, which we will call belief sets. In the present paper we introduce nonmonotonic belief set operators and selection operators to formalize and to analyze structural aspects of reasoning with multiple belief sets. We define and investigate formal properties of belief set operators as absorption, congruence, supradeductivity and weak belief monotony. Furthermore, it is shown that for each belief set operator satisfying strong belief cumulativity there exists a largest monotonic logic underlying it, thus generalizing a result for nonmonotonic inference operations. Finally, we study abstract properties of selection operators connected to belief set operators, which are used to choose some of the possible belief sets. This revised version was published online in June 2006 with corrections to the Cover Date.     

Quantum interference effects at room temperature in OPV-based single-molecule junctions

Interference effects on charge transport through an individual molecule can lead to a notable modulation and suppression on its conductance. In this letter, we report the observation of quantum interference effects occurring at room temperature in single-molecule junctions based on oligo(3)-phenylenevinylene (OPV3) derivatives, in which the central benzene ring is coupled to either para- or meta-positions. Using the break-junction technique, we find that the conductance for a single meta-OPV3 molecule wired between gold electrodes is one order of magnitude smaller than that of a para-OPV3 molecule. Theoretical calculations confirm the occurrence of constructive and destructive interference in the para- and meta-OPV3 molecules respectively, which arises from the phase difference of the transmission coefficients through the molecular orbitals.     

Single‐Material Graphene Thermocouples

On‐chip temperature sensing on a micro‐ to nanometer scale is becoming more desirable as the complexity of nanodevices keeps increasing and their downscaling continues. The continuation of this trend makes thermal probing and management more and more challenging. This highlights the need for scalable and reliable temperature sensors, which have the potential to be incorporated into current and future device structures. Here, it is shown that U‐shaped graphene stripes consisting of one wide and one narrow leg form a single material thermocouple that can function as a self‐powering temperature sensor. It is found that the graphene thermocouples increase in sensitivity with a decrease in leg width, due to a change in the Seebeck coefficient, which is in agreement with previous findings and report a maximum sensitivity of ΔS ≈ 39 μV K^?1.     

A Prototype for Diagnosis of Psoriasis in Traditional Chinese Medicine

Psoriasis is a chronic, non-communicable, painful, disfiguring and disabling disease for which there is no cure, with great negative impact on patients’ quality of life (QoL). Diagnosis and treatment with traditional Chinese medical technique based on syndrome differentiation has been used in practice for a long time and proven effective, though, up to now, there are only a few available studies about the use of semantic technologies and the knowledge systems that use Traditional Chinese Medicine (TCM)-syndrome differentiation for information retrieval and automated reasoning. In this paper we use semantic techniques based on ontologies to develop a prototypical system for the diagnosis of Psoriasis. For this purpose, a domain ontology is developed for syndrome differentiation of psoriasis vulgaris (PV). This ontology is founded on an adapted version of the general formal ontology (GFO), with the evidence-based clinical practice guideline of TCM for psoriasis vulgaris (Guideline 2013) as the primary data sources. The implemented prototype, called ONTOPV, contains this domain ontology and is aimed at a decision support system for diagnosis and treatment of PV. This system uses a case-database for Case Based Reasoning (CBR), combined with fuzzy pattern recognition. Experimental results show that the ONTOPV realizes the basic functionalities of data collection, querying, browsing and navigation, and supports rule-based knowledge reasoning, and integrates fuzzy pattern recognition. It can provide users with clinical decision support for TCM syndrome differentiation in diagnosis of psoriasis.