[en] 3-benzothiazole-9-ethyl-carbazole (BEC) and 3,6-di-benzothiazole-9-ethyl-carbazole (DBEC) were synthesized by using carbazole as base and then characterized by ¹H NMR. The optical properties of them were investigated and compared with carbazole and 9-ethyl-carbazole. The photostability and thermostability of the compounds were studied and the results indicated they are both very stable. Effects of solvent properties including polarity, viscosity and refractive index on the spectra properties of the compounds were investigated. Quantum yield of the compounds in organic solvent was also determined and it is found the most complex compound has the highest quantum yield up to 0.68. Finally the synthesized compounds were used to label bovine serum albumin (BSA) protein and simultaneously stability constant (K_s) between them is calculated and compared with other similar dyes. The results showed that the fluorescent intensity of the compound is increased significantly after labeling with BSA protein. - Highlights: • Synthesis and optical properties of two carbazole-benzothiazole derivatives. • Photostability and thermostability of the compounds and compared the results with each other. • Quantum yields of the compounds and the relationship with the structure. • Protein labeling properties of the compounds and stability constant

[en] Tearing mode real-time active control system has been developed on HL-2A tokamak. During the plasma discharge, electron cyclotron emission and soft X-ray diagnostic signals are used to get the geometric location where tearing modes emerge, combined with the real time profile reconstruction and electron cyclotron wave (ECW) deposition algorithm, the target angle of ECW steering mirror can be obtained. Then the mirror angle is set by the motor so that the ECW power deposit at the position of tearing modes finally. Consequently the tearing modes can be controlled, owing to the change of local current profile, and the plasma confinement is improved. This system has been deployed in HL-2A campaigns after 2015, and the good control effect is obtained. It has been proved that the system can discover and control not only the classical tearing modes in real time, but also has the potential to control the neoclassical tearing mode in the future. (authors)

[en] The HL-2A equilibrium reconstruction subsystem with grid dimension 33 × 33 didn't meet the control accuracy and speed for the HL-2M tokamak, so a new equilibrium reconstruction subsystem with grid dimension 129 × 129 was developed. This subsystem can run a time slice in 600 μs by solving the G-S function and reconstructing some algorithm of calculating some parameters and meet the requirements of the control system about real-time and accuracy on HL-2A and HL-2M tokamak. (authors)

[en] The GPU parallel algorithms of the HL-2A plasma real-time equilibrium reconstruction including parallel processing of G-S equation, an algorithm solving the tri-diagonal linear system efficiently in parallel, the computation of the flux on grid boundary points and some parallel speed-up for middle-scale matrix multiplication on GPU, were introduced. After the parallelization, an equilibrium reconstruction iteration needs around 575 μs with a 129 × 129 grid. (authors)

[en] Real-time equilibrium reconstruction is crucially important for plasma shape control in the process of tokamak plasma discharge. However, as the reconstruction algorithm is computationally intensive, it is very difficult to improve its accuracy and reduce the computation time, and some optimizations need to be done. This article describes the three most important aspects of this optimization: (1) compiler optimization; (2) some optimization for middle-scale matrix multiplication on the graphic processing unit and an algorithm which can solve the block tri-diagonal linear system efficiently in parallel; (3) a new algorithm to locate the X and O point on the central processing unit. A static test proves the correctness and a dynamic test proves the feasibility of using the new code for real-time reconstruction with 129 × 129 grids; it can complete one iteration around 575 μs for each equilibrium reconstruction. The plasma displacements from real-time equilibrium reconstruction are compared with the experimental measurements, and the calculated results are consistent with the measured ones, which can be used as a reference for the real-time control of HL-2A discharge. (paper)

[en] A novel micro resonator optic gyroscope comprising a dual-resonator structure is proposed. This design radically eliminates the noise induced by Rayleigh backscattering, the Kerr effect and polarization coupling. The configuration of the micro optic gyroscope (MOG) is given and described. Three methods are applied to suppress the optical noises in the system and to theoretically analyze the performance improvement. Experiments are carried out on both dual-resonator and single-resonator MOGs, which show the resonance depth improvement from 0.7477 to 0.9173 in the present MOG dual-resonator configuration. (fundamental areas of phenomenology(including applications))

[en] Polyglycolic acid (PGA), a linear aliphatic polyester with excellent biodegradability and biocompatibility, is widely used as a medical material. However, the inherent brittleness of this material may limit its use in many other industrial applications. This study explored the toughening effect of physically blending PGA with polyethylene oxide (PEO). Standard tensile samples of different PGA/PEO blends were prepared by a torque rheometer and a microinjection molding machine. The thermodynamic properties, mechanical properties, and microstructure of the PGA/PEO samples were investigated by differential scanning calorimetry (DSC), a universal tensile testing machine, a cantilever impact tester, and field emission scanning electron microscopy (FE-SEM). The experiment ultimately found that the addition of 15 wt% PEO greatly improved the toughness of the blended PGA/PEO. A yielding process could be observed in the tensile tests, and the elongation-at-break increased from 3.67% for pure PGA to 54.14% for PGA/PEO 85:15, which shows an increase of 1475.2%. It can be concluded that the addition of PEO is a good way to increase the PGA toughness. The mechanism of PGA toughening by PEO was further analyzed, and the increase in toughness could be attributed to the existence of a continuous PEO phase that facilitated the formation and evolution of cavities between the partially compatible PGA and PEO phases.

[en] An integrated optical waveguide resonator based on a SiO₂ waveguide is proposed, fabricated and tested. The method of designing the resonator is also presented. The optimal splitting ratio of the coupler is gained by simulating the relationship between the splitting ratio of the key coupler in the resonator and the resonator's finesse with resonance depth. The calculated fundamental detection limit of this integrated optical waveguide resonator is l.6°/h. Finally, a micro-optical gyroscope system based on the integrated waveguide resonator is built, and the measured resonator's finesse F is close to 70 under fluctuating temperature. To the best of our knowledge, the present F is the best result to date. For the coupler splitting rate the experimental results have fixed errors with the simulation results caused by fabrication processes which can be easily eliminated, implying that the method of design is effective and applicable. (fundamental areas of phenomenology(including applications))

[en] Common CT imaging signs of lung diseases (CISLs) are defined as the imaging signs that frequently appear in lung CT images from patients. CISLs play important roles in the diagnosis of lung diseases. This paper proposes a novel learning method, namely learning with distribution of optimized feature (DOF), to effectively recognize the characteristics of CISLs. We improve the classification performance by learning the optimized features under different distributions. Specifically, we adopt the minimum spanning tree algorithm to capture the relationship between features and discriminant ability of features for selecting the most important features. To overcome the problem of various distributions in one CISL, we propose a hierarchical learning method. First, we use an unsupervised learning method to cluster samples into groups based on their distribution. Second, in each group, we use a supervised learning method to train a model based on their categories of CISLs. Finally, we obtain multiple classification decisions from multiple trained models and use majority voting to achieve the final decision. The proposed approach has been implemented on a set of 511 samples captured from human lung CT images and achieves a classification accuracy of 91.96%. The proposed DOF method is effective and can provide a useful tool for computer-aided diagnosis of lung diseases on CT images. (paper)

[en] Highlights: • A high efficiency WRPTR is proposed and optimized by 1-D simulation. • Acoustic impedance model and dynamic model are applied to analyze the WRPTR. • The performances of the WRPTR and ITPTR are studied and compared. • A relative Carnot efficiency of 20.8% is obtained at 170 K for the WRPTR. -- Abstract: The efficiency of conventional pulse tube refrigerator (PTR) is bounded due to the dissipation of acoustic power at the hot end. Thus, the acoustic power recovery is of great significance for improving the efficiency of the PTR, especially in the application of middle-high temperature zone and large cooling capacity. Based on an existing inertance tube pulse tube refrigerator (ITPTR), a pneumatic piston phase shifter is designed to shift the phase difference and recover part of the acoustic power. The acoustic impedance model and dynamic model are applied to theoretically analyze the work recovery pulse tube refrigerator (WRPTR). Parametric simulation and optimization of the pneumatic piston are performed with the help of the 1-D simulation software (Sage), and the experimental system of WRPTR is successfully built. Some experiments are performed on the experimental system and the experimental results are in good agreement with the simulation results. The experimental results show that the pneumatic piston phase shifter can recover the acoustic power well with a suitable phase relationship. A relative Carnot efficiency of 20.8% is obtained at 170 K with 15 W cooling capacity. In addition, the pneumatic piston phase shifter is lighter and more compact, which is more advantageous in applications.