Heavy metals present in soil and water naturally or as contaminants from human activities can cause bioaccumulation affecting the entire ecosystem and pose harmful health consequences in all life forms. Some famous non-food hyperaccumulators such as Thlaspi caerulescens, Sedum alfredii, Pteris vittata, Arabidopsis halleri and Athyrium yokoscense are of very little economic value, making it difficult for them to be used for phytoremediation. In this paper, the influence of heavy metals Cu, Ni, Zn, Hg, Cr, Pb and Cd on seed germination and early seedling growth in oil crop Eruca sativa was evaluated under laboratory conditions. Our results indicated that among the 7 heavy metals tested, only Ni at higher concentrations (1 mM and above) significantly decreased the Eruca seed germination in a dose-dependent manner. All heavy metals except Zn and Ni decreased the root length first, then the shoot length or the fresh seedling weight, and seed germination was always the last to be influenced. With Ni, the root length, shoot length and fresh seedling weight were stimulated when Ni concentrations were under 1 mM; with Zn, the root length, shoot length and fresh seedling weight were increased by all concentrations tested (0.20 -5.0 mM). Our results indicated that Eruca is tolerant or moderately tolerant to Cu, Hg, Cr, and Cd and highly tolerant to Pb, Ni and Zn, and can be developed as an industrial oil crop for phytoremediation of soils contaminated by heavy metals.

In this paper, a multi-band patch antenna with bandpass filtering response is proposed. The antenna consists of two pairs of crossed dipoles, four Γ-shaped feedlines, and four steeped-impedance microstrip lines. With the introduction of Γ-shaped feedlines and U-shaped slots on the radiating patch, extra radiation nulls are induced, and four operation bands with band-pass filtering response are obtained. More importantly, the filtering response of the antenna is generated without any filtering circuits, which is easy to design for antenna engineers. Measured results of the prototype show that the proposed antenna has stable radiation patterns with low cross-polarization level of better than −26 dBi over the four operation bands. Good filtering response with deep roll-off can also be observed between different operation bands. Excellent radiating performances make it a promising candidate for 5G wireless communication systems.

A dual‐band cavity‐backed circularly polarized crossed‐dipole antenna with double split‐ring resonators (SRRs) is investigated in this paper. A pair of crossed dipoles connected by concentric ring‐delay lines is firstly designed as a circularly polarized (CP) antenna with only one CP mode. To extend the operation of the original design, a pair of the λ/4‐resonance SRRs are used to realize wider axial ratio bandwidth at higher band. At the same time, another pair of the λ/4‐resonance SRRs with larger dimension is adopted to obtain a lower frequency band, although the effect is not very satisfying. Then the cavity‐backed technology and a defected ground structure are both employed to improve the working bandwidth. The dual‐band CP antenna can be tuned into a wide bandwidth one by changing the dimensions of the larger SRRs. A good agreement between the simulated and measured results can be observed. The measured impedance bandwidths are 6.90% (3.36‐3.60 GHz) and 53.58% (4.40‐7.62 GHz). The measured 3‐dB AR bandwidth is 7.93% (3.39‐3.67 GHz) and 59.15% (4.08‐7.51 GHz).

ITO (Indium tin oxide) film has been widely used as transparent electrode for organic light-emitting diodes (OLEDs). Higher conductibility and transparency, smoother surface morphology and higher work function are indispensable for the fabrication of high performance OLEDs, especially for transparent and double-side devices. Therefore, it is necessary to deposit ITO films at low temperature to protect the organic films of OLED from damaging during fabrication process. In this work a novel transparent electrode ITO/Ag/ITO was introduced to the OLED device. This kind of transparent electrode was used to reduce the sheet resistance of electrode and raise the performance of OLED device. By theoretical simulation, the optimum film thickness of three organic layers was obtained. ITO and Ag films were prepared by DC magnetron sputtering at room temperature. The transparent electrode with low sheet resistance of 6.3 Ω/sq and high transmittance of 87% at 550 nm was achieved. OLED consisted of this multilayer film was developed. The relationship between the thickness of Ag film and photoelectric performance of multilayer films was also discussed.