1,782 research outputs found

    Compact Metamaterials Induced Circuits and Functional Devices

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    In recent years, we have witnessed a rapid expansion of using metamaterials to manipulate light or electromagnetic (EM) wave in a subwavelength scale. Specially, metamaterials have a strict limitation on element dimension from effective medium theory with respect to photonic crystals and other planar structures such as frequency selective surface (FSS). In this chapter, we review our effort in exploring physics and working mechanisms for element miniaturization along with the resulting effects on element EM response. Based on these results, we afford some guidelines on how to design and employ these compact meta-atoms in engineering functional devices with high performances. We found that some specific types of planar fractal or meandered structures are particularly suitable to achieve element miniaturization. In what follows, we review our effort in Section 1 to explore novel theory and hybrid method in designing broadband and dual band planar devices. By using single or double such compact composite right-/left-handed (CRLH) atom, we show that many microwave/RF circuits, i.e., balun, rat-race coupler, power divider and diplexer, can be further reduced while without inducing much transmission loss from two perspectives of lumped and distributed CRLH TLs. In Section 2, we show that a more compact LH atom can be engineered by combining a fractal ring and a meandered thin line. Numerical and experimental results demonstrate that a subwavelength focusing is achieved in terms of smooth outgoing field and higher imaging resolution. Section 3 is devoted to a clocking device from the new concept of superscatterer illusions. To realize the required material parameters, we propose a new mechanism by combining both electric and magnetic particles in a composite meta-atom. Such deep subwavelength particles enable exact manipulation of material parameters and thus facilitate desirable illusion performances of a proof-of-concept sample constructed by 6408 gradually varying meta-atoms. Finally, we summarize our results in the last section

    Enhancing the hydrolysis of excess sludge using thermophilic Bacillus sp. Hnu under different oxygen supply conditions

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    A thermophilic Bacillus strain was isolated from excess sludge in the present study. The 16S rDNA analysis indicated that this strain was a Bacillus sp. and has not been reported previously (named Bacillus sp. Hnu). The aim of this paper was to investigate the enhanced efficiency of excess sludge hydrolysis by the addition of thermophilic Bacillus sp. Hnu under different oxygen supply conditions. The results indicated that higher temperature and more oxygen supply was advantageous to the volatile suspended solid removal ratio with the same effect to that of protease activity. The maximum volatile suspended solid removal ratio was achieved at 21.5 %, 42.5 %, and 54.4 % after 108 h digestion at pH 6.9 and 60°C and increased by 17.2 %, 38 %, and 45.4 % under anaerobic, microaerobic, and aerobic conditions compared with the control test, respectively. The hydrolysis rate constants for the anaerobic, microaerobic, and aerobic conditions were 3, 4.8, and 7 times (40°C) and 3.5, 9.8, and 11.8 times (50°C) and 2.7, 7.2, and 10.3 times (60°C). Hydrolysis performance indicated that the Bacillus sp. Hnu could accelerate the hydrolysis rate. The kinetic study showed that the hydrolysis of sludge with Bacillus sp. Hnu and the control test followed the first-order kinetics except at 60°C

    Radioprotective effect and other biological benefits associated with flavonoids

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    Ionizing radiation has the potential to cause extensive damage to living organisms. It can directly act on DNA, proteins and lipids, resulting in ionizing excitation and chemical bond cleavage, which can lead to molecular and cellular damage. Ionizing radiation can hydrolyze water molecules in the body, resulting in increased numbers of free radicals with strong oxidation ability. This process indirectly leads to tissue degeneration and necrosis, which can possibly result in cancer. In this paper, the intervention mechanism of flavonoids on ionizing radiation was analyzed. It has been revealed that the intervention mechanism associated with flavonoids may offer protective properties for DNA, prevent scavenging free radicals, and protect against auto-immune damage. In addition, this invention mechanism can protect the hematopoietic system and reduce inflammationKeywords: Ionizing radiation, Flavonoids, Radioprotective mechanisms, Molecular and cellular damage, DNA, Hematopoietic system, Inflammatio

    Efficient synthesis of Vitamin D3 in a 3D ultraviolet photochemical microreactor fabricated using an ultrafast laser

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    Large-scale, high-precision, and high-transparency microchannels hold great potential for developing high-performance continuous-flow photochemical reactions. We demonstrate ultrafast laser-enabled fabrication of 3D microchannel reactors in ultraviolet (UV) grade fused silica which exhibit high transparency under the illumination of UV light sources of wavelengths well below 300 nm with excellent mixing efficiency. With the fabricated glass microchannel reactors, we demonstrate continuous-flow UV photochemical synthesis of vitamin D3 with low power consumption of the UV light sources

    Alcohol Use, Abuse, and Dependency in Shanghai

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    The use of alcohol for social and ceremonial occasions was recorded in Chinese history as early as 1760 B.C. during the Yin Dynasty (Ci-Hai Encyclopedia, 1979:936). The cultural tradition of ancient China placed alcoholic beverages at the center of social occasions, which presumably was the origin of the adage: Without wine, there is no li (or etiquette). Thus, the use of alcoholic beverages has always been accompanied by the concept of propriety and the discharging of one\u27s role obligations m social functions, rather than that of personal indulgence
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