Memristive operation mode of a site-controlled quantum dot floating gate transistor

The authors gratefully acknowledge financial support from the European Union (FPVII (2007-2013) under Grant Agreement No. 318287 Landauer) as well as the state of Bavaria.We have realized a floating gate transistor based on a GaAs/AlGaAs heterostructure with site-controlled InAs quantum dots. By short-circuiting the source contact with the lateral gates and performing closed voltage sweep cycles, we observe a memristive operation mode with pinched hysteresis loops and two clearly distinguishable conductive states. The conductance depends on the quantum dot charge which can be altered in a controllable manner by the voltage value and time interval spent in the charging region. The quantum dot memristor has the potential to realize artificial synapses in a state-of-the-art opto-electronic semiconductor platform by charge localization and Coulomb coupling.Publisher PDFPeer reviewe

An evaluation of artificial intelligent technologiesfor fault diagnosis in power network

The artificial intelligent technology provides an advanced tool for fault diagnosis in powel networks, and has madegreat progress in the past thirty years. This paper briefly introduces the basic concepts of the intelligent technologies for faultdiagnosis. including expert system, artificial neural network, fuzzy theory, genetic algorithms and Petri net. Based on theseconcepts. the corresponding methods for power network fault diagnosis in the literature are reviewed. Their features andmain problems are discussed for further research and development. 簡要介紹了相關的人工智能技術 ,如專家系統 ( expert system) ,人工神經網絡 ( artificialneural network) ,模糊理論 ( fuzzy theory) ,遺傳算法 ( genetic algorithms)及 Petri網絡 ( Petri net)等的基本概念 ,并在此基礎上對文獻中提出的相應的輸電網絡故障診斷方法進行述評 ,分析它們在輸電網絡故障診斷中應用的特點以及存在的主要問題 ,以促進該研究領域的進一步發

Minimum degree reordering based graph partitioning method for distributed fault section estimation system in power networks

In order to make fault section estimation (FSE) in large-scale power networks use distributed artificial intelligence approach, we have to develop an efficient way to partition the large-scale power network into desired number of connected sub-networks such that each sub-network should have quasi-balanced working burden in performing FSE. In this paper, an efficient minimum degree reordering based graph partitioning method is suggested for the partitioning task. The method consists of two basic steps: partitioning the power network into connected, quasi-balanced and frontier minimized sub-networks based on minimum degree reordering and minimizing the number of the frontier nodes of the sub-networks through iterations so as to reduce the interaction of FSE in adjacent sub-networks. The partitioning procedure and characteristic analysis is presented. The method has been implemented with sparse storage technique and tested in the IEEE 14-bus, 30-bus and 118-bus systems respectively. Computer simulation results show that the proposed multiple-way graph partitioning method is suitable for FSE in large-scale power networks and is compared favorably with other graph partitioning methods suggested in references.published_or_final_versio

Apigenin impedes cell cycle progression at G2 phase in prostate cancer cells

As a natural flavone, apigenin is abundantly present in vegetables, fruits, oregano, tea, chamomile, wheat sprout and is regarded as a major component of the Mediterranean diet. Apigenin is known to inhibit proliferation in different cancer cell lines by inducing G2/M arrest, but it is unclear whether this action is predominantly imposed on G2 or M phases. In this study, we demonstrate that apigenin arrests prostate cancer cells at G2 phase by flow cytometric analysis of prostate cancer cells co-stained for phospho-Histone H3 and DNA. Concurrently, apigenin also reduces the mRNA and protein levels of the key regulators that govern G2-M transition. Further analysis using chromatin immunoprecipitation (ChIP) confirmed the diminished transcriptional activities of the genes coding for these regulators. Unravelling the inhibitory effect of apigenin on G2-M transition in cancer cells provides the mechanistic understanding of its action and supports the potential for apigenin as an anti-cancer agent. Graphical Abstract: [Figure not available: see fulltext.

Nanobubbles at hydrophilic particle–water interfaces

The puzzling persistence of nanobubbles breaks Laplace’s law for bubbles, which is of great interest for promising applications in surface processing, H2 and CO2 storage, water treatment, and drug delivery. So far, nanobubbles are mostly reported on the hydrophobic planar substrates with atom flatness. It remains a challenge to quantify nanobubbles on rough and irregular surfaces due to the lack of characterization technique that can detect both the nanobubble morphology and chemical composition inside individual nanobubble-like objects. Here, by using synchrotron-based scanning transmission soft X-ray microscopy (STXM) with nanometer resolution, we discern nanoscopic gas bubbles > 25 nm with direct in-situ proof of O2 inside the nanobubbles at a hydrophilic particle-water interface under ambient conditions. We find a stable cloud of O2 nanobubbles at the diatomite particle-water interface hours after oxygen aeration and temperature variation. The in situ technique may be useful for many surface nanobubble related studies such as material preparation and property manipulation, phase equilibrium, nucleation kinetics and their relationships with chemical composition within the confined nanoscale space. The oxygen nanobubble clouds may be important in modifying particle-water interfaces and offering breakthrough technologies for oxygen delivery in sediment and/or deep water environment

Induced magnetization in La0.7_{0.7}Sr0.3_{0.3}MnO3_3/BiFeO3_3 superlattices

Using polarized neutron reflectometry (PNR), we observe an induced magnetization of 75$\pm$ 25 kA/m at 10 K in a La$_{0.7}$Sr$_{0.3}$MnO$_3$ (LSMO)/BiFeO$_3$ superlattice extending from the interface through several atomic layers of the BiFeO$_3$ (BFO). The induced magnetization in BFO is explained by density functional theory, where the size of bandgap of BFO plays an important role. Considering a classical exchange field between the LSMO and BFO layers, we further show that magnetization is expected to extend throughout the BFO, which provides a theoretical explanation for the results of the neutron scattering experiment.Comment: 5 pages, 4 figures, with Supplemental Materials. To appear in Physical Review Letter

Investigation of dietary fiber, protein, vitamin E and other nutritional compounds of banana flower of two cultivars grown in China

The nutritional composition of banana flowers of two cultivars [cvs. Baxijiao (AAA) and Paradisical (AAB)] grown in Hainan of China has been studied. Flower samples were collected and extracted according to methods of Association of Official Analytical Chemists (AOAC). Results showed thatbanana flowers contained abundant dietary fiber (4.96-5.74 g/100g) and proteins (1.62-2.07 g/100 g). The major amino acids are glycine, leucine, alanine, and aspartic acid. Lysine had a lowest chemical score of 64% among the essential amino acids. In both species, flowers contained a higher composition of unsaturated fatty acids (65-66%), mainly the linoleic acid, while saturated fatty acids (mainly palmitic acid) is low. The contents of vitamin E, total saponin and flavonoids were 0.87-1.07, 0.12 and 5.27–5.90mg/100 g, respectively. This study provides a fundamental nutritional data of banana flowers which can be essential in food science