28 research outputs found

    Synthesis of supramolecular architectures using Pn-ligands as building blocks

    Get PDF
    In this thesis, chemical properties and coordination behaviors of different Pn-ligand complexes were studied and following aspects are engaged: i) The lone pairs of electrons on the phosphorus atoms in the Pn-ligands give a ligation propensity to transition metal centers, which lead to oligomers or polymers; ii) The ligation mode of P5-nCn-ring (n = 0-2) ligands toward the transition metal centers can be side-on or end-on; iii) The P5-nCn-ring (n = 0-2) of polyphosphaferrocenes during their reactions with transition metal salts can remain intact or fragmentise; iv) Replacement of CR fragments by phosphorus atoms in the P5-nCn-ring (n = 0-2) and different substituent groups on the cyclopentadiene ring additionally coordinated to the iron atom can influence the results of the coordination; and v) different copper halide clusters can be formed in these coordination reactions

    Tetraphosphacyclopentadienyl and Triphosphaallyl Ligands in Iron Complexes [Tetraphosphacyclopentadienyl- und Triphosphaallyl-Liganden in Eisenkomplexen]

    No full text
    Different faces of phosphorus chemistry: The reaction of the bicyclotetraphosphine complex 1 with tBuCP leads to the first 1,2,3,4-tetraphosphaferrocene complex 2 and an allylic P3-bridged complex 3. Cp=5-C5H2tBu3

    Efficient Binary Weight Convolutional Network Accelerator for Speech Recognition

    No full text
    Speech recognition has progressed tremendously in the area of artificial intelligence (AI). However, the performance of the real-time offline Chinese speech recognition neural network accelerator for edge AI needs to be improved. This paper proposes a configurable convolutional neural network accelerator based on a lightweight speech recognition model, which can dramatically reduce hardware resource consumption while guaranteeing an acceptable error rate. For convolutional layers, the weights are binarized to reduce the number of model parameters and improve computational and storage efficiency. A multichannel shared computation (MCSC) architecture is proposed to maximize the reuse of weight and feature map data. The binary weight-sharing processing engine (PE) is designed to avoid limiting the number of multipliers. A custom instruction set is established according to the variable length of voice input to configure parameters for adapting to different network structures. Finally, the ping-pong storage method is used when the feature map is an input. We implemented this accelerator on Xilinx ZYNQ XC7Z035 under the working frequency of 150 MHz. The processing time for 2.24 s and 8 s of speech was 69.8 ms and 189.51 ms, respectively, and the convolution performance reached 35.66 GOPS/W. Compared with other computing platforms, accelerators perform better in terms of energy efficiency, power consumption and hardware resource consumption

    Maternal obesity caused by overnutrition exposure leads to reversal learning deficits and striatal disturbance in rats.

    Get PDF
    Maternal obesity caused by overnutrition during pregnancy increases susceptibility to metabolic risks in adulthood, such as obesity, insulin resistance, and type 2 diabetes; however, whether and how it affects the cognitive system associated with the brain remains elusive. Here, we report that pregnant obesity induced by exposure to excessive high fatty or highly palatable food specifically impaired reversal learning, a kind of adaptive behavior, while leaving serum metabolic metrics intact in the offspring of rats, suggesting a much earlier functional and structural defects possibly occurred in the central nervous system than in the metabolic system in the offspring born in unfavorable intrauterine nutritional environment. Mechanically, we found that above mentioned cognitive inflexibility might be associated with significant striatal disturbance including impaired dopamine homeostasis and disrupted leptin signaling in the adult offspring. These collective data add a novel perspective of understanding the adverse postnatal sequelae in central nervous system induced by developmental programming and the related molecular mechanism through which priming of risk for developmental disorders may occur during early life

    Coordination Behavior of the 1,2,3-Triphosphaferrocene [Cp′′′Fe(η5-P3C2(H)Ph)] with Organometallic Moieties

    No full text
    The reaction of the 1,2,3-triphosphaferrocene [Cp′′′Fe(η5-P3C2(H)Ph)] (1) with the Lewis acidic complex [PtCl2(PEt3)]2 yields the monosubstituted derivative [Cp′′′Fe(η5-P3C2(H)Ph){PtCl2(PEt3)}] (2), in which the Pt moiety is located at the P atom adjacent to the C(H) group of the cyclo-P3C2 ring. Using an excess of the Pt complex no multiple substitution occurs. In contrast, using [W(CO)5] units as Lewis acids results in mono-, di-, and tricoordination at the cyclo-P3C2 ring. The products, [Cp′′′Fe(η5-P3C2(H)Ph){W(CO)5}n] (n = 1 (3), 2 (4), 3 (5)), have all been spectroscopically characterized, and the substitution patterns of the experimentally found (mono- and disubstituted) isomers are found to be in accordance with the energetically favored derivatives calculated by DFT methods. For these structures the energetically favored rotational conformers have also been calculated. The energetically favored 2,3-coordinated isomer 4b could be crystallized, and its structure and that of the tricoordinated derivative 5 were determined by X-ray diffraction methods

    Synthesis and unprecedented coordination behaviour of a novel 1,2,3-triphosphaferrocene complex

    No full text
    A novel 1,2,3-triphosphaferrocene has been synthesised, which reacts with CuBr to give a 2D polymer, revealing an unprecedented -stacking of the triphospholyl moieties
    corecore