364 research outputs found

    The Role of Waste Glass Powder During the Hydration Process of Composite Cementitious Materials

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    The role of waste glass powder (GP) during the hydration process of composite cementitious materials was investigated by using mercury intrusion porosimetry (MIP), X-ray diffraction (XRD) and scanning electron microscopy (SEM) techniques. The compressive strength was also tested. The results indicate that the chemical activity of GP is low. But the pozzolanic reactivity of GP greatly improves with its fineness and the elevated curing temperature, which contributes to improving the mechanical strength. The hydration process of composite cementitious material containing GP is similar to that of pure cement. With the increase of GP content in the composite cement, the occurring time of second exothermic improves, but the value of second exothermic peak and the cumulative hydration heat reduce. The characteristic pore size of pastes containing GP decreases over curing age, which significantly improves their strength. GP does not modify the type of hydration products of composite cementitious material. The microstructure of hardened pastes containing GP is dense due to the generation of C-S-H gel with a low Ca/Si ratio. There is a reaction ring along GP with high fineness, which can enhance the interfacial transition zone to avoid ASR

    Adaptive Control of Space Robot Manipulators with Task Space Base on Neural Network

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    As are considered, the body posture is controlled and position cannot control, space manipulator system model is difficult to be set up because of disturbance and model uncertainty. An adaptive control strategy based on neural network is put forward. Neural network on-line modeling technology is used to approximate the system uncertain model, and the strategy avoids solving the inverse Jacobi matrix, neural network approximation error and external bounded disturbance are eliminated by variable structure control controller. Inverse dynamic model of the control strategy does not need to be estimated, also do not need to take the training process, globally asymptotically stable of the closed-loop system is proved based on the lyapunov theory. The simulation results show that the designed controller can achieve high control precision has the important value of engineering application

    Non-gapless excitation and zero-bias fast oscillations in the LDOS of surface superconducting states

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    Recently a novel surface pair-density-wave (PDW) superconducting state has been discovered in Refs. [Phys. Rev. Lett. \textbf{122}, 165302 (2019)] and Phys. Rev. B \textbf{101}, 054506 (2020)], which may go through a distinct multiple phase transition (MPT) when the superconductivity fades away from bulk to the boundary (e.g. edges and corners). Based on the Bogoliubov-de Gennes equations for the attractive tight-binding Hubbard modal in a one-dimensional chain, we demonstrate that the surface PDW state has a non-gapless quasiparticle spectrum, which is contrary to the conventional surface superconducting state. Moreover, we find that the MPT is associated with a zero-bias fast oscillating pattern in the LDOS near the surface. Our findings provide a potential experimental clue to identify the surface PDW state.Comment: 4 figure

    Study on SDN Technology Based on OpenFlow and Its Application Prospect

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    Openflow-based SDN separates the control plane of the network from the data plane of the switch and router, providing a new idea for the future development of the Internet. This paper starts with the connotation of OpenFlow and SDN, analyzes the key technologies of SDN, and prospects the application prospect of SDN

    Fake News? A Survey on Video News Releases and their Implications on Journalistic Ethics, Independence and Credibility of Broadcast News

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    The traditional lines between journalism and public relations are now intertwined and public relations practitioners have an influential role on the content consumers see every day in newspapers and on news broadcasts. This survey looked at video news releases and their implications about journalists’ ethics, integrity, independence and credibility. 533 participants from three different populations (average viewers, communication college students, and journalists) responded to a 54-question survey that employed two predictors (i) level of experience and (ii) years of journalism experience. The results indicated that average viewers found the use of video news releases (VNRs) more unethical than journalists and communication students, although experienced journalists believed VNR use is having an impact on journalistic independence in news. Implications are discussed

    Efficacy of consensus interferon in treatment of HbeAg-positive chronic hepatitis B: a multicentre, randomized controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Consensus interferon (CIFN) is a newly developed type I interferon.</p> <p>Aims</p> <p>This multicentre, controlled trial was conducted to determine the efficacy of CIFN and to compare it with alpha-1b-interferon (IFN-α1b) in the treatment of patients with hepatitis B e antigen (HBeAg)-positive chronic hepatitis B.</p> <p>Methods</p> <p>144 Patients were randomly assigned to receive 9 μg CIFN (CIFN group) or 50 μg INF-α1b (IFN-alpha group) subcutaneously 3 times weekly for 24 weeks, followed by 24 weeks of observation. Efficacy was assessed by normalization of serum alanine transaminase (ALT) levels and the non-detectability of serum hepatitis B virus DNA or HBeAg at the end of treatment and 24 weeks after stopping treatment.</p> <p>Results</p> <p>There was no statistically significant difference in the serological, virological and biochemical parameters between CIFN and IFN-α1b groups at the end of the therapy and follow-up period (p > 0.05). Overall, at the end of treatment, 7.0% (5/71) and 35.2% (25/71) of patients in the CIFN group showed a complete or partial response compared with 7.4% (5/68) and 33.8% (23/68) of the IFN-alpha group (p = 0.10). At 24 weeks after stopping treatment, 6.9% (5/72) and 37.5% (27/72) of patients in the CIFN group showed complete response or partial response compared with 7.1% (5/70) and 34.3% (24/70) of the IFN-alpha group (p = 0.10).</p> <p>Conclusion</p> <p>These findings suggest that 9 μg CIFN is effective in the treatment of patients with HBeAg-positive chronic hepatitis B. It can gradually induce ALT normalization and HBV DNA clearance and HBeAg loss or HBeAg/HBeAb seroconversion.</p
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