Interface design for high energy density polymer nanocomposites

This review provides a detailed overview on the latest developments in the design and control of the interface in polymer based composite dielectrics for energy storage applications. The methods employed for interface design in composite systems are described for a variety of filler types and morphologies, along with novel approaches employed to build hierarchical interfaces for multi-scale control of properties. Efforts to achieve a close control of interfacial properties and geometry are then described, which includes the creation of either flexible or rigid polymer interfaces, the use of liquid crystals and developing ceramic and carbon-based interfaces with tailored electrical properties. The impact of the variety of interface structures on composite polarization and energy storage capability are described, along with an overview of existing models to understand the polarization mechanisms and quantitatively assess the potential benefits of different structures for energy storage. The applications and properties of such interface-controlled materials are then explored, along with an overview of existing challenges and practical limitations. Finally, a summary and future perspectives are provided to highlight future directions of research in this growing and important area

Numerical modelling and observations of nuclear-explosion coda wavefields

Frequency-dependent earthquake coda attenuation values are often reported; however such measurements usually depend on the types of the attenuation models employed. In this thesis, I use numerical modeling of Peaceful Nuclear Explosion (PNE) codas at far regional to teleseismic distances to compare two of such models, namely the conventional frequency-dependent attenuation with parameters (Q0, ¦Ç) defined by Qcoda(f) = Q0f¦Ç and frequency-independent effective attenuation (Qe) with geometrical attenuation (¦Ã). The results favour strongly the (¦Ã, Qe) model and illustrate the mechanisms leading to apparent Qcoda(f) dependencies. Tests for variations of the crustal velocity structures show that the values of ¦Ã are stable and related to lithospheric structural types, and the inverted Qe values can be systematically mapped into the true Swave attenuation factors within the crust. Modeling also shows that ¦Ã could increase in areas where relatively thin attenuating layers are present within the crust; such areas could likely be related to younger and active tectonics. By contrast, when interpreted by using the traditional (Q0,¦Ç) approach, the synthetic coda shows a strong and spurious frequency dependence with ¦Ç ¡Ö 0.5, which is also similar to many published observations. Observed Lg codas from two Peaceful Nuclear Explosions located in different areas in Russia show similar values of ¦Ã ¡Ö 0.75¡¤10-2 s-1, which are also remarkably close to the independent numerical predictions in this thesis. At the same time, coda Qe values vary strongly, from 850 in the East European Platform to 2500 within the Siberian Craton. This suggests that parameters ¦Ã and Qe could provide stable and transportable discriminants for differentiating between the lithospheric tectonic types and ages, and also for seismic coda regionalization in nuclear-test monitoring research

Intrinsic tuning of poly (styrene-butadiene-styrene) (SBS) based self-healing dielectric elastomer actuators with enhanced electromechanical properties

The electromechanical properties of a thermoplastic styrene-butadiene-styrene (SBS) dielectric elastomer was intrinsically tuned by chemical grafting with polar organic groups. Methyl thioglycolate (MG) reacted with the butadiene block via a one-step thiol-ene ‘click’ reaction under UV at 25°C. The MG grafting ratio reached 98.5 mol% (with respect to the butadiene alkenes present) within 20 minutes and increased the relative permittivity to 11.4 at 103 Hz, with a low tan δ. The actuation strain of the MG grafted SBS dielectric elastomer actuator was ten times larger than the SBS-based actuator, and the actuation force was four times greater than SBS. The MG grafted SBS demonstrated an ability to achieve both mechanical and electrical self-healing. The electrical breakdown strength recovered to 15% of its original value, and the strength and elongation at break recovered by 25% and 21%, respectively, after three days. The self-healing behaviour was explained by the introduction of polar MG groups that reduce viscous loss and strain relaxation. The weak CH/π bonds through the partially charged (δ+) groups adjacent to the ester of MG and the δ- centre of styrene enable polymer chains to reunite and recover properties. Intrinsic tuning can therefore enhance the electromechanical properties of dielectric elastomers and provides new actuator materials with self-healing mechanical and dielectric properties

Study of multiple degrees of freedom entanglement in optical fiber

The orbital angular momentum (OAM) has attracted widespread attention due to its ability to carry information in multiple dimensions. However, a high-dimensional entanglement carrying OAM can be affected by environment and undergoes decoherence. Ensuring the stability and high fidelity of entangled states after transmission is a crucial part of quantum communication. How to control the entangled states are essential. In this paper, we produce the polarization entangled photon pairs by type I BBO crystals by means of spontaneous parametric down-conversion (SPDC), we achieve the polarization-OAM hybrid entangled states by q-plate (QP) by means of manipulating the multi-degrees of freedom of the quantum state after passing through the APD communication channel. The polarization entangled photon pairs have the characteristics of OAM. We use polarization degree of freedom to modulate OAM degree of freedom, our polarization-OAM hybrid entangled states can slow down the reduction of the fidelity in the during of transmission process. Our quantum states exhibit a superior level of fidelity contrast with the conventional situation. This method will provide a theoretical guidance for improving the transmission fidelity of OAM states in fiber.Comment: 9 pages, 8 figures, 42 reference

Network centrality, knowledge searching and creativity: The role of domain

This study aims to determine the role of knowledge searching on creativity in the fields of science research and technology development. Creativity is a process of knowledge combination, thus internal and external knowledge searching is important for creativity in both fields, particularly in the open innovation age. However, the nature of the work across these fields is different. While science research aims to solve theoretical problems and generate new knowledge, technology development aims to apply new knowledge to solve practical problems. Compared to science research, technology development has clear task goals, which make it easier to identify the related external knowledge and integrate this knowledge and in turn improve employee creativity. Thus, employees\u27 attention to external knowledge as well as the influence of external knowledge on creativity might be different in the two fields. Results based on an empirical study of 211 employees from science research and 257 employees from technology development showed that external knowledge searching increased employee creativity in the field of technology development but not in science research. Furthermore, employees\u27 centrality in the intra-team problem-solving network moderated the relationship between external knowledge searching and creativity in the science research field. Suggestions about employee creativity management in science and technology fields are discussed

Characterization of Adenocarcinoma\u27s Autofluorescence Properties Using Multiexcitation Analysis Method

General purpose of this research is to get an early cancer detection method based on the properties of optical analysis between normal and adenocarsinoma tissue using the multiexcitation autofluorescence method. Observation of autofluorescence properties was done on the biopsy sample of adenocarcinoma tissues, GR mice transplanted by adenocarsinoma, and cell culture SM 1. Excitation on tissue was done by using  the lamp Light Emitting Diode (LED) at some visible light wavelength range. This research obtained that the value of Intensity Auto fluorescence (IAF) at range red wavelength of cells and adenocarsinoma tissues tend to lower compared to the cells normal tissues if its were excited by blue LED. On the contrary, the value of IAF at infra red wavelength from cells and carcinoma tissues tend to higher compared to the cells and normal tissues if its were excited by red LED

ErbB2 is required for cardiomyocyte proliferation in murine neonatal hearts

It has been long recognized that the mammalian heart loses its proliferative capacity soon after birth, yet, the molecular basis of this loss of cardiac proliferation postnatally is largely unknown. In this study, we found that cardiac ErbB2, a member of the epidermal growth factor receptor family, exhibits a rapid and dramatic decline in expression at the neonatal stage. We further demonstrate that conditional ablation of ErbB2 in the ventricular myocardium results in upregulation of negative cell cycle regulators and a significant reduction in cardiomyocyte proliferation during the narrow neonatal proliferative time window. Together, our data reveal a positive correlation between the expression levels of ErbB2 with neonatal cardiomyocyte proliferation and suggest that reduction in cardiac ErbB2 expression may contribute to the loss of postnatal cardiomyocyte proliferative capacity

Generation of True Quantum Random Numbers with On-Demand Probability Distributions via Single-Photon Quantum Walks

Random numbers are at the heart of diverse fields, ranging from simulations of stochastic processes to classical and quantum cryptography. The requirement for true randomness in these applications has motivated various proposals for generating random numbers based on the inherent randomness of quantum systems. The generation of true random numbers with arbitrarily defined probability distributions is highly desirable for applications, but it is very challenging. Here we show that single-photon quantum walks can generate multi-bit random numbers with on-demand probability distributions, when the required ``coin'' parameters are found with the gradient descent (GD) algorithm. Our theoretical and experimental results exhibit high fidelity for various selected distributions. This GD-enhanced single-photon system provides a convenient way for building flexible and reliable quantum random number generators. Multi-bit random numbers are a necessary resource for high-dimensional quantum key distribution