Non-interacting spherical active particles under confinement: generalized entropy potential

We study the transport of self-propelled noninteracting active Brownian particles (ABPs) and run-and-tumble particles (RTPs) in a long tube with varying widths. We obtain a generalized Fick-Jacobs equation for the active particles under the condition of slow varying width and wide tubes. In the passive limit, it is equivalent to particles moving in a generalized entropy potential. The entropy potential resembles its counterpart for passive particles, with the activity changing the effective temperature and the effective width of the tube. The generalized entropy potential enables estimations of 1D steady-state density along the tube and the mean escape time out of a spindle chamber.Comment: 6 pages, 5 figure

A critical review on the study of threatening in English

Despite the fact that threatening in languages is common in ordinary verbal communication, it has not received much attention from academic studies because of its “negative” nature. Muschalik’s monograph Threatening in English: A Mixed Method Approach, mainly based on the theory of Face Threatening Speech Act by Brown and Levinson (1987), takes 301 categories of threatening expressions in judicial proceedings as the corpus with qualitative and quantitative methods, brings a new perspective for pragmatic research, especially speech act research, and deepens people’s understanding of relevant issues. Initiated by Muschalik’s book Threatening in English: A Mixed Method Approach, the paper is to make a critical review on the studies of threatening in English and propose some new directions for the study of threatening in languages

Activated escape of a self-propelled particle from a metastable state

We study the noise-driven escape of active Brownian particles (ABPs) and run-and-tumble particles (RTPs) from confining potentials. In the small noise limit, we provide an exact expression for the escape rate in term of a variational problem in any dimension. For RTPs in one dimension, we obtain an explicit solution, including the first sub-leading correction. In two dimensions we solve the escape from a quadratic well for both RTPs and ABPs. In contrast to the equilibrium problem we find that the escape rate depends explicitly on the full shape of the potential barrier, and not only on its height. This leads to a host of unusual behaviors. For example, when a particle is trapped between two barriers it may preferentially escape over the higher one. Moreover, as the self-propulsion speed is varied, the escape route may discontinuously switch from one barrier to the other, leading to a dynamical phase transition

Study on nonlinear detection and identification for rubber isolation bearing

The isolation bearing nonlinear mechanical model is described based on the simplified Bouc-wen hysteresis model. In order to provide reasonable mechanical properties state assessment for isolation bearing of base isolated structure under seismic excitation, wavelet coefficient energy ratio index are proposed to detect the time-domain evolution characteristics during the nonlinear phase of isolation bearing, then the nonlinear characteristics and parameters of the isolation bearing are identified using wavelet multi-resolution analysis theory. Numerical examples show that the wavelet coefficient energy ratio (WCER) can be a good way to detect the nonlinear states of the isolation bearing under different seismic excitation levels, and the nonlinear characteristics and the model parameters of the isolation bearing can be accurately identified by using the wavelet multi-resolution identification methods

Melanocortin 1 receptor targeted imaging of melanoma with gold nanocages and positron emission tomography

Purpose: Melanoma is a lethal skin cancer with unmet clinical needs for targeted imaging and therapy. Nanoscale materials conjugated with targeting components have shown great potential to improve tumor delivery efficiency while minimizing undesirable side effects in vivo. Herein, we proposed to develop targeted nanoparticles for melanoma theranostics. Method: In this work, gold nanocages (AuNCs) were conjugated with α-melanocyte-stimulating hormone (α-MSH) peptide and radiolabeled with 64Cu for melanocortin 1 receptor-(MC1R) targeted positron emission tomography (PET) in a mouse B16/F10 melanoma model. Results: Their controlled synthesis and surface chemistry enabled well-defined structure and radiolabeling efficiency. In vivo pharmacokinetic evaluation demonstrated comparable organ distribution between the targeted and nontargeted AuNCs. However, micro-PET/computed tomography (CT) imaging demonstrated specific and improved tumor accumulation via MC1R-mediated delivery. By increasing the coverage density of α-MSH peptide on AuNCs, the tumor delivery efficiency was improved. Conclusion: The controlled synthesis, sensitive PET imaging, and optimal tumor targeting suggested the potential of targeted AuNCs for melanoma theranostics. </jats:sec

The Excitation of Guided-waves by Underground Point Source: an Investigation with Theoretical Seismograms

AbstractNear-Source scattering of Rg into S appears to be the primary contributor to the low-frequency Lg. The authors further suggest that the prominent low-frequency spectral null in Lg is due to Rg from a compensated linear vector dipole (CLVD) source, and the low-frequency null in Rg excitation is due to a zero-crossing of the horizontal displacement eigenfunctions. In this study, the mechanism of the excitation of Lg from explosions in layered earth structures are analyzed with theoretical seismograms. Our result shows that the CLVD source generates prominent Lg waves,and the null in the Lg spectra showing remarkably good agreement with those expected from Rg due to a CLVD source. We conclude that the derivative of displacement eigenfunction also takes a key role in the excitation of the null, only zero-crossing of the horizantall displacement eigenfunction can not fully explain it

EmoFake: An Initial Dataset for Emotion Fake Audio Detection

Many datasets have been designed to further the development of fake audio detection, such as datasets of the ASVspoof and ADD challenges. However, these datasets do not consider a situation that the emotion of the audio has been changed from one to another, while other information (e.g. speaker identity and content) remains the same. Changing the emotion of an audio can lead to semantic changes. Speech with tampered semantics may pose threats to people's lives. Therefore, this paper reports our progress in developing such an emotion fake audio detection dataset involving changing emotion state of the origin audio named EmoFake. The fake audio in EmoFake is generated by open source emotion voice conversion models. Furthermore, we proposed a method named Graph Attention networks using Deep Emotion embedding (GADE) for the detection of emotion fake audio. Some benchmark experiments are conducted on this dataset. The results show that our designed dataset poses a challenge to the fake audio detection model trained with the LA dataset of ASVspoof 2019. The proposed GADE shows good performance in the face of emotion fake audio

Stability analysis and performance improvement of power sharing control in Islanded microgrids

Due to the requirement of synchronism and power sharing, droop control and its variations have become one essential component for distributed generator (DG)-powered microgrids. However, the power sharing accuracy and system stability margin may be threatened by the randomness from the load demand and renewable generation. In this paper, a dynamic stability analysis is first performed on a DG-powered microgrid through a produced system frequency response model (SFR). The results point out that (i) the critical system eigenvalues directly vary with the system operating condition; (ii) a fixedgain power sharing control is prone to be less damped and loses stability easily under some operating conditions. Then, the heuristic adaptive dynamic programming (HDP) strategy is used for power sharing control with the benefit of adapting to realtime disturbances and uncertainties. Through Lyapunov theorem, stability analysis is provided to demonstrate the reliability of the HDP-based power sharing control in islanded microgrids. Finally, simulation tests verify the analysis results and demonstrate the favorable performance of the HDP-based power sharing control under uncertain load disturbances