A field experiment was conducted to study the effects of microbial agents and built-in straw biological reactor technology on solar greenhouse soil temperature and the growth of winter tomato(Lycopersicon esculentum Mill.).The results showed that after using the microbial agents,built-in straw biological reactor technology and both methods can increasing soil temperature by 0.28,0.85 ℃ and 1.23 ℃,respectively.The built-in straw biological reactor technology,and applying both of them could dramatically speed up the winter tomato growth,and increase the tomato yield by 10.7% and 11.8%.
Abstract Microwave absorbing materials play an increasingly important role in modern electronic warfare technology for enhancing electromagnetic compatibility and suppressing electromagnetic interference. High‐entropy ceramics (HECs) possess extraordinary physical and chemical properties, and more importantly, the high tunability of multi‐component HECs has brought new opportunities to microwave absorbing materials. Rich crystallographic distortions and multi‐component occupancies enable HECs to have highly efficient microwave absorption properties, excellent mechanical properties, and thermal stability. Therefore, the structural advantages of HECs are integrated from comprehensive perspectives, emphasizing on the role of dielectric and magnetic properties in the absorption phenomenon. Strategies are proposed to improve the microwave absorption capacity of HECs, including composition optimization, microstructure engineering, and post‐treatment technology. Finally, the problems and obstacles associated with high‐entropy materials (HEMs) research are discussed. The innovative design concepts of high‐entropy microwave absorbing ceramics are highlighted.
ADT7301is a13-bit digital temperature sensor produced by Analogy Device Corporation.It has wide power supplyvoltage range from3.3Vto5Vand is characteristic ofhigh accuracy,lowdissipation and flexiˉble serial interface.The primary features and the requirements of the device are introduced in the paper.The interface circuits between the ADT7301and the microcontroller are designed,and the corresponding application programs are also given.
In order to meet the requirements of UHV transmission and ultra-large capacity, Safety and reliability, developing a new type of high voltage and low cost insulation material has been the key problem in the development of UHV transmission equipment. In this paper, the dielectric properties of a new polymer cement concrete insulation material have been studied. The component and the manufacture process of PCC insulations have been optimized and the samples have been made. Breakdown test, volume resistivity, dielectric spectroscopy and space charge measurement have been used to study its dielectric properties. As shown in the test results, the breakdown strength of the PCC insulations can reach up to 11 kV/mm, its volume resistivity is around 10 12 Ω·cm. Its permittivity decreases with the frequency and the dielectric loss can reach a peak value upon 1 Hz and then starts to decrease. As seen from the space charge measurement results, homocharge can be found in the vicinity of the electrode and heterocharge accumulates in the middle region and the total amount of the accumulated charge increases with time.
We report an experimental investigation in the laser-induced damage threshold (LIDT) of optical coatings materials. The samples are single layers of Al2O3, Nb2O5, HfO2, SiO2, Ta2O5, ZrO2 deposited through different deposition techniques (evaporation or sputtering with/without ion assistance) and mixtures of Al2O3/SiO2, Nb2O5/SiO2, HfO2/SiO2, Ta2O5/SiO2 and ZrO2/SiO2 on silica substrates. The LIDT is measured at 1030nm, 500fs in single shot mode. The results are expressed and compared in term of LIDT as a function of bandgap and LIDT as a function of refractive index.
Ultra-black coating has more than 99 % absorbance and is widely applied in aerospace, optical instruments, and solar industries. However, preparing the presently available ultra-black coatings requires high temperatures, significantly limiting their application. Based on a resin-matrix composite coating filled with carbon nanotubes (CNTs), this study provides a new method for preparing resin-matrix ultra-black coatings using laser etching technology at room temperature. The obtained results indicated that the laser etching process could effectively remove the pure resin film coated on the coating surface and change the light contact interface from air/resin to air/CNTs. The highest average absorption achieved by the coating was 99.49 %. The morphological characteristics prove that the laser etching changed the coating surface from a smooth resin to a porous microstructure. The porous microstructure played a significant role in light absorption and remarkably improved surface roughness and hydrophobicity. In addition, the excellent light absorption performance significantly improved the photothermal conversion, which translated to enhanced anti-icing and anti-frosting performance over an aluminum substrate. Under 1 sun illumination at -10 °C, the frozen time of water drop on the coating surface was 692 s, 11.2 times longer than that on an aluminum substrate surface. No frosting was observed on the coating surface after 600 s of testing. Furthermore, the coating also showed remarkable anti-icing and anti-frosting performance at -20 °C. Hence, the reported ultra-black layer demonstrated room-temperature synthesis and extremely high light absorbance, making it a promising candidate for various cold-weather applications.
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