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Building change detection (CD) from remote sensing images (RSI) has great significance in exploring the utilization of land resources and determining the building damage after a disaster. This article proposed an attention-based multiscale input–output network, named AMIO-Net, for building CD in high-resolution RSI. It is able to overcome partial drawbacks of existing CD methods, such as insufficient utilization of information (details of building edges) of original images and poor detection effect of small targets (small-scale buildings or small-area changed buildings that are disturbed by other buildings). In AMIO-Net, the input image is scaled down to different sizes, and performed the convolution to extract features. Then, the feature maps are fed into the encoding stage so that the network can fully utilize the feature information (FI) of the original image. More importantly, we design two attention mechanism modules: the pyramid pooling attention module (PPAM) and the Siamese attention mechanism module (SAMM). PPAM combines a pyramid pooling module and an attention mechanism to fully consider the global information and focus on the FI of changed pixels in the image. The input of SAMM is the parallel multiscale output diagram of the decoding portion and deep feature maps of the network so that AMIO-Net can utilize the global contextual semantic FI and strengthen detection ability for small targets. Experiments on three datasets show that the proposed method achieves higher detection accuracy and F1 score compared with the state-of-the-art methods.

The helicon plasma source is of great significance for the magnetoplasma rocket engine (MPRE) to be used as an effective propulsion device. In this paper, a multi-fluid, two-dimensional, axisymmetric model coupled with the electromagnetic field was developed to simulate the helicon plasma source in the MPRE. The simulation results demonstrate that the operation mode of the helicon plasma source in the MPRE gradually converts to a high-order wave mode and the resonance between the electromagnetic field and electrons is observed; due to the resonance, the deposit power density inside the plasma increases significantly, and the plasma density is two orders of magnitude higher than that in the inductively coupled plasma source. As the magnetic field intensity increases, the helicon plasma source enters into a high-order wave mode, which suggests that the MPRE can improve the utilization rate of the working medium by a stronger magnetic field.

Based on the suppressor of cytokine signaling 1 (SOCS1)/Janus kinase (JAK)/signal transducer and activator of transcription 3 (STAT3) pathway, the mechanism of oxymatrine in the treatment of atopic dermatitis (AD) was preliminarily explored in this study. C57BL/6 mice were induced to establish AD model by smearing carbotriol (MC903) on their back. The AD mice were randomly divided into model group, oxymatrine groups with three dosages (25, 50 and 100 mg/kg), (n = 10). Oxymatrine groups were intragastric administered once daily for 14 days. The same volume of saline was given in the normal control group and model group once daily for 14 days. Subsequently, HE staining was used to observe the pathological changes of skin tissue, ELISA was used to detect the levels of serum inflammatory factors including interleukin-4, 6 and 17 (IL-4, IL-6, and IL-17), tumor necrosis factor-α (TNF-α) and immunoglobulin E (IgE). Immunohistochemistry was used to detect the expression of suppressor of cytokine signaling 1 and CD3 in skin tissue, and Western blotting was used to detect the proteins in suppressor of cytokine signaling 1/JAK-STAT3 pathway. Compared with the normal control group, the pathological damage of mice in the model group, such as skin hyperplasia, edema, congestion and inflammatory infiltration, aggravated increased significantly. And the expression of serum inflammatory factors, CD3 positive expression and JAK-STAT3 pathway protein in the model group were increased (p < .05), and the expression of suppressor of cytokine signaling 1 protein (p < .05) was decreased. Compared with the model group, the above pathological damage of the mice was reduced, and the serum inflammatory factors, JAK-STAT3 pathway protein, and CD3 positive expression were decreased as a dose-dependant manner (p < .05), and the expression of suppressor of cytokine signaling 1 protein was increased as a dose-dependent manner (p < .05). Oxymatrine can improve the skin inflammation symptoms of AD mice by up regulating the expression of suppressor of cytokine signaling 1, inhibiting the activation of JAK-STAT3 pathway and blocking the activation of T lymphocytes.

The electromagnetic sail, a new space propulsion system without propellant, which propels a spacecraft by deflecting solar wind with an electromagnetic field, is proposed. The thrust mechanism and the performance variations of the electromagnetic sail are analyzed with both particles in cell and magnetohydrodynamic models, and the interaction between the incoming plasma fluid and the electromagnetic field is investigated by tests on the ground experimental system. The simulation results demonstrate that a magnetosphere is created in front of the sail and its area increases with magnetic field intensity; with appropriate dipole moment, the thrust of the electromagnetic sail is higher than a pure magnetic sail or a pure electric sail. In test experiments, the plume structure of a helicon plasma source changes obviously with coil current and metal mesh voltage, which verifies the repulsion of the magnetic field and electric field to the incoming plasma. These results indicate that the combination of the magnetic sail and electric sail can increase the utilization efficiency of solar wind, which means the electromagnetic sail is a feasible propulsion system.

Particle separation is important in chemical and biomedical analysis. Among all particle separation approaches, microstructure filtration which based particles size difference has turned into one of the most commonly methods. By controlling the movement of particles, dielectrophoresis has also been widely adopted in particle separation. This work presents a microfluidic device which combines the advantages of microfilters and dielectrophoresis to separate micro-particles and cells. A three-dimensional (3D) model was developed to calculate the distributions of the electric field gradient at the two filter stages. Polystyrene particles with three different sizes were separated by micropillar array structure by applying a 35-Vpp AC voltage at 10 KHz. The blocked particles were pushed off the filters under the negative dielectrophoretic force and drag force. A mixture of Haematococcus pluvialis cells and Bracteacoccus engadinensis cells with different sizes were also successfully separated by this device, which proved that the device can separate both biological samples and polystyrene particles.

Pleurotus ostreatus (Jacq. :Pers.) Roll is a grey edible mushroom (Agaricochaete), containing a variety of vitamins, minerals and different kind of secondary metabolites. Two new terpenoid indole alkaloids (Terpendole N and Terpendole O) were isolated from the fermentation of P. ostreatus. Their structures were elucidated by 1D, 2D NMR, HR-ESI-MS, and ECD. [ABSTRACT FROM AUTHOR]

Using high-energy electron beams to ionize air is an effective way to produce a large-size plasma in the atmosphere. In particular, with a steady-state high power generator, some unique phenomena can be achieved, including natural convection of the plasma. The characteristics of this convection are studied both experimentally and numerically. The results show that an asymmetrical temperature field develops with magnitudes that vary from 295K to 389K at a pressure of 100 Torr. Natural convection is greatly enhanced under 760 Torr. Nevertheless, plasma transport is negligible in this convection flow field and only the plasma core tends to move upward. Parameter analysis is performed to discern influencing factors on this phenomenon. The beam current, reflecting the Rayleigh number Ra effect, correlates with convection intensity, which indicates that energy deposition is the underlying key factor in determining such convections. Finally, natural convection is concluded to be an intrinsic property of the electron beam when focused into dense air, and can be achieved by carefully adjusting equipment operations parameters. [ABSTRACT FROM AUTHOR]

To extract circular array targets from high-spatial resolution optical satellite images, we propose an efficient two-step detection framework. In the first stage, we propose a multiscale histogram contrast (MHC) saliency evaluation model to detect salient objects. This saliency model is able to highlight all salient areas with well-defined boundaries and effectively suppress the obvious background textures. Moreover, the generated saliency map can be used to find the locations of potential targets most likely causing visual attention, which greatly decreases the computation cost in later processes. In the second stage, we extract task-related targets from these salient objects by removing the irrelevant salient areas according to the special properties of the targets. In this paper, we present a circular array targets-detection method based on the saliency map produced by the proposed saliency detector. First we extract the circular objects from the saliency map using simple shape features, which are then clustered through a graph-based approach to locate the target areas. To evaluate the performance of our saliency model and targets extraction scheme, we carried out many experiments on large-field, high-spatial resolution remote-sensing images and achieved promising results both in efficiency and precision. [ABSTRACT FROM AUTHOR]

A self-consistent, diffusion-drift approximated fluid model including ion and electron continuity equations and an electron energy equation is presented for simulating the nonequilibrium characteristics during breakdown of argon rf glow discharge. The nonlinear partial differential equations of the model are solved numerically by using a so-called finite volume method. The numerical results indicate that there exist two different phases on the breakdown curves, i.e., the low p·d phase and high p·d phase. The breakdown voltage, analyzed for three different gaps, varies little in low p·d phase while in the high p·d phase, it increases linearly with pressure increase. Time evolution of Ohmic heating and energy loss during breakdown are presented in detail. Analysis yields that the heating mechanisms are the dominant factors in breakdown. Moreover, the steady discharge characteristics are also studied specifically under breakdown voltage of 10 Torr. The charged particle densities are on the order of 1015/m3 and the electron energy has two characteristic values at different rf phases. [ABSTRACT FROM AUTHOR]