A broadband circularly polarized antenna array is proposed in this paper. The array consists of four sequentially rotated feed groove-backed strip antennas. Compact size (46 mm×46 mm×1.6 mm), wide impedance bandwidth (4.62-9.92 GHz), and wide 3 dB axial ratio bandwidth (4.48-8.52 GHz) can be observed. The measured peak gain is 7.5 dBi at 8.2 GHz, and good agreement between the simulated and measured results can be achieved.
The adsorption of particulate matter (PM) by the leaves of urban plants can effectively reduce the particulate matter concentration in the atmosphere. The use of climbing plants to abate particulate matter is an important means of urban greening in China, which is rich in climbing plant species. In this study, three evergreen climbing plants were selected to assess their ability to adsorb particulate matter and determine their physiological responses to particulate pollution. PM deposition was determined gravimetrically. There were four key results. 1) The adsorption capacity of the three evergreen climbers followed the order of Hedera nepalensis var > Ficus pumila Linn > Euonymus fortunei, and was significantly higher in an overpass environment than in a campus environment for all three species. 2) The seasonal characteristics of particulate adsorption by the three types of climbers in both the overpass and campus environments followed the order of winter > autumn > spring > summer. 3) The net photosynthetic rate of the three climbing plants was significantly affected by particulate matter in a size dependent manner, with fine particulate matter on the plant leaf surface and coarse particulate matter in the leaf waxy layer being important factors affecting plant photosynthesis. 4) Particulate pollution led to changes in the activities of plant protective enzymes in plants, with increases in the superoxide dismutase (SOD) and peroxidase (POD) activity, and the malondialdehyde (MDA) and soluble protein contents. There were different trends in the soluble sugar content among the different plant species. In conclusion, F. pumila had a strong resistance to particulate pollutants, while H. nepalensis was considered suitable for planting in polluted areas where it could improve ambient air quality by adsorbing large amounts of particulate matter.
A two-element dual-band flexible multiin multi-out antenna which can be used for wearable applications is proposed in this paper. The antenna consists of two radiating elements fed by coplanar waveguide, and a shielding layer, which are all made of flexible conductive cloth MKKTN260. Each radiating element is composed of two coupled split ring-shaped bending strips. The proposed antenna shows two measured impedance bandwidth (S 11 <−10 dB) of 2.39-2.48 GHz and 5.72-5.88 GHz, so that it can be used for 2.4 GHz and 5.8 GHz ISM (industrial scientific medical) applications. The two coupled split rings form a self-isolation enhancement structure and can realize polarization diversity at 2.4 GHz band and radiation shielding at 5.8 GHz band, respectively. High isolation (>30 dB) has been achieved for both the bands. Other characteristics for wearable applications like gain, efficiency, specific absorption rate, and bending performances were also studied.
With the continuous development of construction technology in China’s super-tall buildings, the construction of super-tall buildings has gradually expanded from first-tier cities to second-tier and third-tier cities. In order to create green super high-rise buildings, in addition to the rational use of key technologies in design and operation, it is also necessary to correctly grasp the current standard regulations for green buildings and green construction. According to relevant requirements and evaluation standards, correspondingly propose green the main points of construction technology, and at the same time put forward ideas for the application of clean and renewable energy in the construction process according to the current national conditions.
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