Abstract: The seamounts usually have important effects on sound propagation in deep water. A sound propagation experiment was conducted in the South China Sea in 2016. One of the experimental goals is to investigate the three-dimensional(3D) effects of seamounts on sound propagation. Phenomena about horizontal refraction of acoustic waves are observed in different propagation tracks which go through the seamount along different directions when the source depth is 200 m. Ray methods (BELLHOP N×2D and 3D models) which can calculate sound field efficiently and show clear physical images, are used to analyze and explain the causes of the phenomena. The experimental and numerical results show that the convergent zone structures are destroyed by the direct blockage of seamount due to the multiple reflection of acoustic waves, which leads to the increase of transmission loss (TL), and horizontal-refraction zone with obvious boundaries appears behind the seamount. Some experiment phenomena cannot be explained by BELLHOP N×2D model in which the horizontal refraction effects are not taken into consideration. The experimental sound field structure behind the seamount is obviously different from N×2D model numerical result, i.e.the width of shadow zone based on the experimental data is wider than that calculated by N×2D model, and the width of strong horizontal-refraction zone from the experiment is narrower than the N×2D model result. Moreover, the TLs calculated by N×2D model is about 10 dB less than the experimental result in horizontal refraction zone. After analyzing the difference between experimental data and N×2D model numerical results by BELLHOP 3D model which contains the azimuth-coupling capability, it can be concluded that sound waves reach the receiver through horizontal refraction after the interaction with seamount when the source is located behind the seamount. The eigenrays obtained from 3D model are less than N×2D model numerical result because some of sound beams cannot reach the receiver as a result of the horizontal refraction effects, which leads to the experimental TLs larger than the numerical results calculated by N×2D model. Therefore, 3D effect of seamount has an obvious influence on sound field within a certain angle range behind the seamount, and the investigation of 3D effects of seamounts is meaningful for the sound propagation and target detection in deep water.

Abstract: Sound propagation in shallow water is significantly influenced by geoacoustic properties. Estimating these geoacoustic parameters is essential for sound field analysis and sonar performance assessment. As a common practice, the seafloor is often treated as a single-layer or two-layer range-independent geoacoustic model to reduce the number of involved parameters. However, acoustic parameters inverted through these two geoacoustic models are typically limited in their applicability to a specific frequency range, thus posing challenges when applied across a broader frequency range. A range-dependent multi-layer geoacoustic model based on experimental measurements obtained with a sub-bottom profiler is proposed in this study. The inversion scheme combines three inversion methods to estimate geoacoustic parameters, considering the different sensitivities of geoacoustic parameters to different physical parameters within the acoustic field. Firstly, modal dispersion is used to invert the geoacoustic parameters of each layer, with the dispersion curve obtained through warping transform and the Wigner-Ville distribution. After that, both the localization using matched field processing and the dispersion curve fitting demonstrate the effectiveness of the inversion results for each layer, although the peak of the probability distribution of sound speed in the first layer is broader than in others. Secondly, matched field processing is employed to invert the geoacoustic parameters of the first layer. This method is based on the theory that as frequency increases, the depth of sound rays penetrating the seabed decreases, revealing changes in the first layer's sound speed with the seabed depth. Lastly, bottom attenuation coefficients at different frequencies are inverted by the transmission loss (TL), and a fitting relationship between the attenuation coefficient and the frequency is derived. The inversion results obtained by using the range-dependent multi-layer geoacoustic model are compared with results estimated by the single-layer geoacoustic model. The findings indicate that the transmission loss (TL) error from the range-dependent multi-layer geoacoustic model in this study is smaller than that from the single-layer geoacoustic model, especially in the lower frequency band. The range-dependent multi-layer geoacoustic model proves to be suitable for a broader frequency range, providing better precision in explaining various acoustic phenomena.

Abstract: We numerically calculate Luttinger liquid parameter 〈i〉K〈/i〉 in the anisotropic spin XXZD models with spin 〈inline-formula〉〈tex-math id="M15"〉\begin{document}$s = 1/2$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M15.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M15.png"/〉〈/alternatives〉〈/inline-formula〉, 1, and 2. In order to obtain groundstate wavefunctions in Luttinger liquid phases, we employ the 〈inline-formula〉〈tex-math id="M16"〉\begin{document}$U(1)$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M16.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M16.png"/〉〈/alternatives〉〈/inline-formula〉 symmetric infinite matrix product states algorithm (iMPS). By using relation between the bipartite quantum fluctuations 〈i〉F〈/i〉 and the so-called finite-entanglement scaling exponents 〈inline-formula〉〈tex-math id="M17"〉\begin{document}$\kappa$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M17.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M17.png"/〉〈/alternatives〉〈/inline-formula〉, the Luttinger liquid parameter 〈i〉K〈/i〉 can be extracted. For 〈inline-formula〉〈tex-math id="M18"〉\begin{document}$s = 1/2$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M18.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M18.png"/〉〈/alternatives〉〈/inline-formula〉 and 〈inline-formula〉〈tex-math id="M19"〉\begin{document}$D=0$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M19.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M19.png"/〉〈/alternatives〉〈/inline-formula〉, the numerically extracted Luttinger liquid parameter 〈i〉K〈/i〉 is shown to be good agreement with the exact value. On using the fact that the spin-1 XXZD Hamiltonian with 〈inline-formula〉〈tex-math id="M20"〉\begin{document}$ D \leqslant - 2$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M20.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M20.png"/〉〈/alternatives〉〈/inline-formula〉 can be mapped to an effective spin-1/2 XXZ model, we calculate the Luttinger liquid parameter for the region of 〈inline-formula〉〈tex-math id="M21"〉\begin{document}$ D \leqslant - 2$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M21.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M21.png"/〉〈/alternatives〉〈/inline-formula〉. It is shown that our numerical value of the Luttinger liquid parameter agree well with the exact values, here, the relative error less than 〈inline-formula〉〈tex-math id="M22"〉\begin{document}$1\%$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M22.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M22.png"/〉〈/alternatives〉〈/inline-formula〉. Also, our Luttinger liquid parameter at 〈inline-formula〉〈tex-math id="M23"〉\begin{document}$\Delta = - 0.5$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M23.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M23.png"/〉〈/alternatives〉〈/inline-formula〉 and 〈inline-formula〉〈tex-math id="M24"〉\begin{document}$ D = 0$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M24.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M24.png"/〉〈/alternatives〉〈/inline-formula〉 is shown to be consistent with the result form the density matrix renormalization group (DMRG) method. These results suggest that the 〈inline-formula〉〈tex-math id="M25"〉\begin{document}$U(1)$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M25.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M25.png"/〉〈/alternatives〉〈/inline-formula〉 symmetric iMPS method can be applicable to calculate Luttinger liquid parameters if any system has a 〈inline-formula〉〈tex-math id="M26"〉\begin{document}$U(1)$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M26.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M26.png"/〉〈/alternatives〉〈/inline-formula〉 symmetry for gapless phases. For instance, we present our Luttinger liquid parameters for the first time for the spin-1 XXZD model under the other parameters and the spin-2 XXZD model with 〈inline-formula〉〈tex-math id="M27"〉\begin{document}$D = 1.5$\end{document}〈/tex-math〉〈alternatives〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M27.jpg"/〉〈graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="16-20190379_M27.png"/〉〈/alternatives〉〈/inline-formula〉.

Abstract: In the numerical calculation, the projected entangled pair state (PEPS) algorithm is the most important tensor network algorithm for two-dimensional strongly correlated electron quantum lattice system. In this paper, the optimization of PEPS for two-dimensional quantum system is discussed. An optimization connection between how to update the PEPS tensor and how to calculate the physical observable is investigated, for the tensor network algorithm based on the PEPS representation, which can greatly improve the utilization of computing resources. In this case, optimized PEPS algorithm, as a powerful tool, can be used to study quantum phase transitions and quantum critical phenomena in the thermodynamic limit of the two-dimensional strongly correlated electron quantum lattice system. Of course, optimization of PEPS algorithm program has many other applications, such as adding U(1) and SO(2) symmetry in PEPS algorithm, etc.

Abstract: The electro-optical properties of polymer dispersed liquid crystal film vary with liquid crystal content and externally applied electric field, but the analysis of the film morphology cannot directly reflect the mechanism of electro-optical properties. Therefore, the polymer dispersed liquid crystal film prepared by blending liquid crystal material E7 and photopolymer NOA65 is used. Herein, the dielectric polarization regulated electro-optical properties and their related mechanisms under different liquid crystal content and electric fields are revealed. The results show that in a frequency range of 10〈sup〉–1〈/sup〉–10〈sup〉6〈/sup〉 Hz, the film exhibits three relaxation processes respectively at low frequency, medium frequency and high frequency, which are generated by thermionic polarization, interfacial polarization and orientation polarization. According to the Arrhenius equation, the activation energy values of such polarization processes are calculated. It is found that with the increase of liquid crystal content, the activation energy of orientation polarization decreases from 0.88 eV to 0.83 eV, leading the threshold field strength and the saturation field strength of the diversion of liquid crystal molecule to decrease. Thermionic polarization under DC electric field forms an internal electric field, which causes the threshold field strength and saturation field strength to increase greatly, as compared with the scenarios under AC electric field. Such a thermionic polarization also leads the polarization relaxation time to increase, resulting in the extension of response time. This study is of guiding significance in further analyzing and improving the electro-optical properties of polymer dispersed liquid crystal films.

Abstract: Ｓｉｎｇｌｅｅｌｅｃｔｒｏｎｄｅｖｉｃｅｓｈａｖｅｂｅｅｎｐｒｅｐａｒｅｄｂｙｔｈｅｍｏｌｅｃｕｌａｒｓｅｌｆ ａｓｓｅｍｂｌｙｔｅｃｈｎｉｑｕｅａｎｄｔｈｅｉｒｖｏｌｔａｇｅ ｃｕｒｒｅｎｔｃｈａｒａｃｔｅｒｉｓｔｉｃｓｍｅａｓｕｒｅｄ .Ｏｎｔｈｅｏｔｈｅｒｈａｎｄ,ｓｉｎｇｌｅｅｌｅｃｔｒｏｎｄｅｖｉｃｅｓｗｅｒｅｓｔｕｄｉｅｄｂｙｔｈｅＭｏｎｔｅＣａｒｌｏｓｉｍｕｌａｔｉｏｎｂａｓｅｄｏｎａｓｅｍｉ ｃｌａｓｓｉｃａｌｔｈｅｏｒｙｏｆｓｉｎｇｌｅｅｌｅｃｔｒｏｎｐｈｅｎｏｍｅｎａ.Ｔｈｅｓｉｍｕｌａｔｄｖｏｌｔａｇｅ ｃｕｒｒｅｎｔｃｕｒｖｅｉｓｓｉｍｉｌａｒｔｏｔｈｅｍｅａｓｕｒｅｄｏｎｅ.Ｔｈｉｓｓｈｏｗｓｔｈａｔｔｈｅａｂｏｖｅｍｅｔｈｏｄｍａｙｂｅｕｓｅｄｔｏｓｔｕｄｙｓｉｎｇｌｅｅｌｅｃｔｒｏｎｄｅｖｉｃｅｓ.Ｆｕｒｔｈｅｒｍｏｒｅ ,ｔｈｅｓｉｍｕｌａｔｄｒｅｓｕｌｔｓｉｎｄｉｃａｔｅｔｈａｔｔｈｅｖｏｌｔａｇｅ ｃｕｒｒｅｎｔｃｈａｒａｃｔｅｒｉｓｔｉｃｏｆａｓｉｎｇｌｅｅｌｅｃｔｒｏｎｄｅｖｉｃｅｉｓｄｅｔｅｒｍｉｎｅｄｏｎｌｙｂｙｔｈｅｓｍａｌｌｑｕａｎｔｉｔｙｏｆｎａｎｏｐａｒｔｉｃｌｅｓｉｎｔｈｅｌｏｗｖｏｌｔａｇｅｒｅｇｉｏｎｔｈｏｕｇｈｔｈｅｒｅａｒｅａｌａｒｇｅｎｕｍｂｅｒｏｆｎａｎｏｐａｒｔｉｃｌｅｓｂｅｔｗｅｅｎｔｈｅｔｗｏｅｌｅｃｔｒｏｄｅｓ.

Abstract: Realization of high performance of EXL-50U plasma rely on neutral beam heating sensitively, which means the beam ions should have a good confinement. The paper gives unacceptable ripple loss results, both on beam ion loss fraction and localized heat load, based on equilibrium, beam ion distribution and ripple data in integrated modeling. The optimization method consist of lower the ripple perturbation amplitude, increase the plasma current and optimization of NBI injection geometry. Calculation results indicate the plasma region should move to high field side and FI to lower the ripple field, increase the Ip above 600kA, beam ion loss fraction can be lower to 3-4%, heat load down to one magnitude. The paper conclude the method of fast ion ripple loss evaluation, including phase space and full calculation within one slowing down time. Also in the paper have other direction of how to lower ripple loss when design a new facility, this will help for integrated modeling and plasma operation.

Abstract: Establishment and sustainment of the structure of internal transport barriers (ITBs) is an important guarantee for the magnetic fusion plasmas. The related physics process for the establishing and sustaining of ITBs with $q_{min} \simeq$ 2 is simply summarized:the "off-axis sawteeth" (OAS) and double tearing modes instability, fast ions induced Alfvén eigenmodes, thermal pressure gradient induced low-frequency modes (LFMs) instability, etc. Firstly, the burst of "off-axis sawteeth" (OAS) is an important criterion for the evaluating of reversed $q$-profile with $q_{min} \simeq$ 2. The excitation conditions, classification and the structure of precursor mode of OAS are given in detailed, and the collapse event is triggered by the magnetic reconnection of $m$/$n$=2/1 double tearing modes (DTM). Secondly, the beta-induced Alfvén eigenmodes (BAEs) and reversed shear Alfvén eigenmodes (RSAEs) are easily excited by the fast ions during the oscillation of OAS. The toroidal mode numbers of the two kinds of Alfvén waves are 1 $\leq n \leq$ 5, which are located at 1.98 $\leq R \leq$ 2.07 m with normalized minor radius 0.2 $\leq \rho \leq$ 0.45. The excitation conditions are investigated for the condition of $q_{min} \simeq$ 2:and three different physical variables of thermal pressure gradient, fast ions distribution function, and the toroidal flow or flow shear are considered. Thirdly, the low-frequency modes (LFMs) instabilities are excited by the pressure gradient during the oscillation of OAS. The general fishbone like dispersion relationship (GFLDR) is adopted for solving the basic features of LFMs:① the frequency of LFMs scale with ions diamagnetic frequency; ② the LFMs has the Alfvén polarization direction; ③ the LFMs are reactive-type kinetic ballooning modes. The excitation of LFMs is not relied on the fast ions, which is taken place at higher pressure gradient regime $\alpha \propto (1 + \tau) (1 + \eta_i)$, $\tau=T_e/T_i$, $\eta_i=L_{n_i}/L_{T_i}$. In the end, the suppression of OAS and establishment of ITBs are achieved. Three important processes are contained for the condition of $q_{min} \simeq$ 2 in EAST:① the tangential injection (NBI1L) of NBI is more easier for the suppression of OAS in comparison with the perpendicular injection (NBI1R); ② the micro-instability can be suppressed during the oscillation of OAS, and the reversed shear $q$-profile is more favorable in the establishment of the structure of ITBs; ③ the establishment of ITBs is accompanied by the excitation of Alfvén waves instabilities (bigger toroidal mode number:1 $\leq n \leq$ 5), the sustainment of ITBs is accompanied by the thermal ions temperature gradient induced instability (median size:5 $\leq n \leq$ 10). Therefore, understanding the establishment and suppression of OAS, the excitation of Alfvén wave instability and the redistributed fast ions, the related instability of thermal pressure gradient, which are important for the establishment of ITBs.

Abstract: Photoionization and dissociative photoionization of HFC-152a have been studied using synchrotron radiation and a reflectron time-of-flight mass spectrometry (RTOF-MS). The ionization energy of parent molecule (11.94±0.04eV) and appearance potentials of various fragment ions have been determined by measuring their photoionization efficiency curves. Energies, symmetry point groups and ground electronic states of neutrals and cations of parent and its fragments have been calculated using GAUSSIAN-03 program with the G3 method. According to the theoretical and experimental results, some dissociation channels and their dissociation energies of CH3CHF+2 have been analyzed.

Abstract: Absolute photoabsorption spectrum of CO molecule in the region 14—20 eV(620—890 Å) is measured using synchrotron radiation and multi-stage photoionization chamber, and its ionization energy is obtained. According to the absorption spectrum of CO and theoretical calculation, the Rydberg series converging to the Χ2Σ+, Α2Π, and B2Σ+ states of CO+ are assigned separately. Rydberg series assigned before are extended, Rydberg series converging to the Χ2Σ+ (ν+=2 and 3) of CO+, and n=2 (the real value of n is 3) progressions of the series converging to the Α2Π state of CO+ are identified. At the same time, the absorption spectrum of CO in the region 17.0—17.5 eV (710—730 Å) is also discussed deeply.