High-Performance Transparent Ultrabroadband Electromagnetic Radiation Shielding from Microwave toward Terahertz.

In the era of fifth-generation networks and Internet-of-Things, the use of multiband electromagnetic radiation shielding is highly desirable for next-generation electronic devices. Herein, we report a systematic exploration of optoelectronic behaviors of ultrathin-silver-based shielding prototype (USP) film structures at the nanometer scale, unlocking the transparent ultrabroadband electromagnetic interference (EMI) shielding from microwave to terahertz frequencies. A theoretical model is proposed to optimize USP structures to achieve increased transparency, whereby optical antireflection resonances are introduced in dielectrics in conjunction with remarkable EMI shielding capability. USP can realize a state-of-the-art effective electromagnetic radiation shielding bandwidth with measured frequencies from 8 GHz up to 2 THz. Experimental results show that a basic USP (dAg = 10 nm) offers an average shielding efficiency of ∼27.5 dB from the X- to Ka-bands (8-40 GHz) and maintains a stable shielding performance of ∼22.6 dB across a broad range of 0.5-2 THz, with a measured optical transmittance of ∼95.2%. This extraordinary performance of ultrathin-silver-based film structures provides a new ultrabroadband EMI shielding paradigm for potential applications in next-generation electronics.

Label-free focusing of viral particles under a temperature gradient coupled with continuous swirling flow.

The advances of biomedicine and biotechnology demand new approaches to enrich biological nanoparticles, such as viruses, viral vectors and nanovesicles, in an easy-to-operate fashion. Conventional methods, such as ultracentrifugation and ultrafiltration, require bulky instruments and extensive manual operation. Inspired by recent research of thermophoresis of biomolecules and bio-nanoparticles in aqueous solutions, we present a microfluidic design that directly focuses nanoparticles in a label-free and flow-through process by coupling an engineered swirling flow and a moderate, one-dimensional temperature gradient. Enrichment of polystyrene particles, HIV and bacteriophage samples was quantitatively determined, indicating the compatibility of the microfluidic approach with synthetic and biological samples. The focusing results are well predicted using a numerical model. As thermophoresis is ubiquitous, the microfluidic approach can be applied broadly to bio-nanoparticle enrichment without the necessity of labeling, buffer exchange, or sheath fluids, permitting continuous retrieval of concentrated species in a simple, controlled flow with little infrastructure needs.

Gain enhancement of BiCMOS on-chip sub-THz antennas by mean of meta-cells.

A MM-loaded sub-THz on-chip antenna with a narrow beamwidth, 9 dB gain and a simulated peak efficiency of 76% at the center frequency of 300 GHz is presented. By surrounding the antenna with a single MM-cell ring defined solely on the top metal of the back-end of line, an efficient suppression of the surface waves is obtained. The on-chip antenna has been designed using IHPs 130 nm SiGe BiCMOS technology with a 7-layer metallization stack, combined with the local backside etching process aimed to creating an air cavity which is then terminated by a reflective plane. By comparing the measured MM-loaded antenna performances to its non-MM-loaded counterpart, an enhanced integrity of the main lobe due to the MM-cells shielding effect can be observed. An excellent agreement between the simulated and measured performances has been found, which makes the MM-loaded antennas a valid alternative for the upcoming next-generation sub-THz transceivers.

Optically transparent and microwave diffusion coding metasurface by utilizing ultrathin silver films.

The past few years have witnessed the great success of artificial metamaterials with effective medium parameters to control electromagnetic waves. Herein, we present a scheme to achieve broadband microwave low specular reflection with uniform backward scattering by using a coding metasurface, which is composed of a rational layout of subwavelength coding elements, via an optimization method. We propose coding elements with high transparency based on ultrathin doped silver, which are capable of generating large phase differences (∼180°) over a wide frequency range by designing geometric structures. The electromagnetic diffusion of the coding metasurface originates from the destructive interference of the reflected waves in various directions. Numerical simulations and experimental results demonstrate that low reflection is achieved from 12 to 18 GHz with a high angular insensitivity of up to ±40° for both transverse electric and transverse magnetic polarizations. Furthermore, the excellent visible transparency of the encoding metasurface is promising for various microwave and optical applications such as electronic surveillance, electromagnetic interference shielding, and radar cross-section reduction.

A Fault Diagnosis Method Considering Meteorological Factors for Transmission Networks Based on P Systems.

Bad meteorological conditions may reduce the reliability of power communication equipment, which can increase the distortion possibility of fault information in the communication process, hence raising its uncertainty and incompleteness. To address the issue, this paper proposes a fault diagnosis method for transmission networks considering meteorological factors. Firstly, a spiking neural P system considering a meteorological living environment and its matrix reasoning algorithm are designed. Secondly, based on the topology structure of the target power transmission network and the action logic of its protection devices, a diagnosis model based on the spiking neural P system considering the meteorological living environment is built for each suspicious fault transmission line. Following this, the action messages of protection devices and corresponding temporal order information are used to obtain initial pulse values of input neurons of the diagnosis model, which are then modified with the gray fuzzy theory. Finally, the matrix reasoning algorithm of each model is executed in a parallel manner to obtain diagnosis results. Experiment results achieved out on IEEE 39-bus system show the feasibility and effectiveness of the proposed method.

Morphological features of colorectal sessile serrated adenoma/polyp under white light endoscopy and narrow band imaging / 中国内镜杂志

Objective To investigate the morphological features of colorectal sessile serrated adenoma/polyp (SSA/P) by white light endoscopy (WLE) and narrow band imaging (NBI). Methods A retrospective analysis was made on the morphological characteristics of SSA/P from January 2014 to March 2017, and compared with HP. Results There were 50 cases of SSA/P from 41 patients and 50 cases of HP from 43 patients. SSA/P located in the right colon was more than HP, but the difference was no statistical significance (16 cases vs 14 cases,P > 0.05). SSA/P have 11 cases of Type Is, 21 cases of Type IIa, 16 cases of Type IIb, 2 cases of Type LST, HP have 17 cases of Type Is, 25 cases of Type IIa, 8 cases of Type IIb, there was no significant difference (P > 0.05); SSA/P has more mucus than HP (37 cases vs 11 cases, P < 0.05). In NBI: The proportion of SSA/P with a red mucus cap, indistinctive borders, irregular shape, black dots inside the crypts, Cloud-like surface, Type II-O pit pattern and varicose microvascular vessels were higher than that of HP (P < 0.05). In the differential prediction of SSA/P and HP: Black dots inside the crypts (OR