Application of Neural-Like P Systems With State Values for Power Coordination of Photovoltaic/Battery Microgrids

The power coordination control of a photovoltaic/battery microgrid is performed with a novel bio-computing model within the framework of membrane computing. First, a neural-like P system with state values (SVNPS) is proposed for describing complex logical relationships between different modes of Photovoltaic (PV) units and energy storage units. After comparing the objects in the neurons with the thresholds, state values will be obtained to determine the con guration of the SVNPS. Considering the characteristics of PV/battery microgrids, an operation control strategy based on bus voltages of the point of common coupling and charging/discharging statuses of batteries is proposed. At rst, the SVNPS is used to construct the complicated unit working modes; each unit of the microgrid can adjust the operation modes automatically. After that, the output power of each unit is reasonably coordinated to ensure the operation stability of the microgrid. Finally, a PV/battery microgrid, including two PV units, one storage unit, and some loads are taken into consideration, and experimental results show the feasibility and effectiveness of the proposed control strategy and the SVNPS-based power coordination control models

Overestimation of thermal emittance in solenoid scans due to coupled transverse motion

The solenoid scan is a widely used method for the in-situ measurement of the thermal emittance in a photocathode gun. The popularity of this method is due to its simplicity and convenience since all rf photocathode guns are equipped with an emittance compensation solenoid. This paper shows that the solenoid scan measurement overestimates the thermal emittance in the ordinary measurement configuration due to a weak quadrupole field (present in either the rf gun or gun solenoid) followed by a rotation in the solenoid. This coupled transverse dynamics aberration introduces a correlation between the beam's horizontal and vertical motion leading to an increase in the measured 2D transverse emittance, thus the overestimation of the thermal emittance. This effect was systematically studied using both analytic expressions and numerical simulations. These studies were experimentally verified using an L-band 1.6-cell rf photocathode gun with a cesium telluride cathode, which shows a thermal emittance overestimation of 35% with a rms laser spot size of 2.7 mm. The paper concludes by showing that the accuracy of the solenoid scan can be improved by using a quadrupole magnet corrector, consisting of a pair of normal and skew quadrupole magnets.Comment: 12 pages, 13 figure

Experiments on bright field and dark field high energy electron imaging with thick target material

Using a high energy electron beam for the imaging of high density matter with both high spatial-temporal and areal density resolution under extreme states of temperature and pressure is one of the critical challenges in high energy density physics . When a charged particle beam passes through an opaque target, the beam will be scattered with a distribution that depends on the thickness of the material. By collecting the scattered beam either near or off axis, so-called bright field or dark field images can be obtained. Here we report on an electron radiography experiment using 45 MeV electrons from an S-band photo-injector, where scattered electrons, after interacting with a sample, are collected and imaged by a quadrupole imaging system. We achieved a few micrometers (about 4 micrometers) spatial resolution and about 10 micrometers thickness resolution for a silicon target of 300-600 micron thickness. With addition of dark field images that are captured by selecting electrons with large scattering angle, we show that more useful information in determining external details such as outlines, boundaries and defects can be obtained.Comment: 7pages, 7 figure

Mechanosensitive Piezo1 protein as a novel regulator in macrophages and macrophage-mediated inflammatory diseases

Macrophages are the most important innate immune cells in humans. They are almost ubiquitous in peripheral tissues with a large variety of different mechanical milieus. Therefore, it is not inconceivable that mechanical stimuli have effects on macrophages. Emerging as key molecular detectors of mechanical stress, the function of Piezo channels in macrophages is becoming attractive. In this review, we addressed the architecture, activation mechanisms, biological functions, and pharmacological regulation of the Piezo1 channel and review the research advancements in functions of Piezo1 channels in macrophages and macrophage-mediated inflammatory diseases as well as the potential mechanisms involved

Noninvasive Measurement and Evaluation of Arterial Stiffness

Abstract-For the purpose of measurement and evaluation of arterial stiffness, we design a noninvasive medical device based on the oscillometric method and the pulse wave velocity (PWV) method, and employ arterial stiffness index (ASI) and PWV as accessing parameters. The inner pressure signal of cuff on the upper arm and the pulse wave signal at the tip of finger will be sampled, and the special software can utilize these signals to calculate two accessing parameters and obtain the evaluation conclusion of arterial stiffness. The clinical experiments show that this medical device and evaluation method are effective and valuable

The Impact of Multidimensional Distance on Agricultural Exports: Evidence from China Based on the Technological Added Value

Agricultural exports are vulnerable to many distance factors such as geographical, cultural, economic and institutional distance. Panel data were collected from 63 countries (from 2002 to 2020), and fixed effects regression models were employed to estimate the impact of multidimensional distance on China’s agricultural exports. Results found that the institutional, geographical, and cultural distance negatively impacted China’s agricultural exports significantly. The economic distance significantly promoted exports due to the demand and complementarity of trade between countries. After the technological added value is considered, the cultural distance significantly promoted the export of high-tech agricultural products. It is confirmed that the institutional distance remained the greatest obstacle to agricultural exports, and economic distance promoted agricultural exports. It is imperative to focus on promoting mutual cultural understanding and communication of institutional policies to stimulate agricultural exports and improve the exports of agricultural products of high technological content

Theoretical analysis and simulation study of the deep overcompression mode of velocity bunching for a comblike electron bunch train

Premodulated comblike electron bunch trains are used in a wide range of research fields, such as for wakefield-based particle acceleration and tunable radiation sources. We propose an optimized compression scheme for bunch trains in which a traveling wave accelerator tube and a downstream drift segment are together used as a compressor. When the phase injected into the accelerator tube for the bunch train is set to ≪-100°, velocity bunching occurs in a deep overcompression mode, which reverses the phase space and maintains a velocity difference within the injected beam, thereby giving rise to a compressed comblike electron bunch train after a few-meter-long drift segment; we call this the deep overcompression scheme. The main benefits of this scheme are the relatively large phase acceptance and the uniformity of compression for the bunch train. The comblike bunch train generated via this scheme is widely tunable: For the two-bunch case, the energy and time spacings can be continuously adjusted from +1 to -1  MeV and from 13 to 3 ps, respectively, by varying the injected phase of the bunch train from -220° to -140°. Both theoretical analysis and beam dynamics simulations are presented to study the properties of the deep overcompression scheme

Structure Evolution and Properties Modification for Reaction-Bonded Silicon Carbide

Complex structure reaction-bonded silicon carbide (RB-SiC) can be prepared by reactive melt infiltration (RMI) and digital light processing (DLP). However, the strength and modulus of RB-SiC prepared by DLP are not sufficient, due to its low solid content (around 40 vol.%), compared with the traditional fabrication techniques (solid content > 60 vol.%). With this understanding, a new method to improve the properties of RB-SiC was proposed, by the impregnation of composite precursor into the porous preform. The composite precursor was composed of phenolic (PF) resin and furfuryl alcohol (FA). PF and FA were pyrolyzed at 1850 °C to obtain amorphous carbon and graphite into the porous preform, respectively. The effects of multiphase carbon on the microstructure and performance of RB-SiC was studied. When the mass ratio of PF to FA was 1/4, the solid content of RB-SiC increased from 40 vol.% to 68.6 vol.%. The strength, bulk density and modulus were 323.12 MPa, 2.94 g/cm3 and 348.83 Gpa, respectively. This method demonstrated that the reaction process between liquid Si and carbon could be controlled by the introduction of multiphase carbon into the porous preforms, which has the potential to regulate the microstructure and properties of RB-SiC prepared by additive manufacturing or other forming methods