Research Progress on Intrinsically Conductive Polymers and Conductive Polymer-Based Composites for Electromagnetic Shielding.

Electromagnetic shielding materials are special materials that can effectively absorb and shield electromagnetic waves and protect electronic devices and electronic circuits from interference and damage by electromagnetic radiation. This paper presents the research progress of intrinsically conductive polymer materials and conductive polymer-based composites for electromagnetic shielding as well as an introduction to lightweight polymer composites with multicomponent systems. These materials have excellent electromagnetic interference shielding properties and have the advantages of electromagnetic wave absorption and higher electromagnetic shielding effectiveness compared with conventional electromagnetic shielding materials, but these materials still have their own shortcomings.

Graphene-Based Metamaterial Sensor for Pesticide Trace Detection.

Organophosphate insecticides with broad spectrum and high efficiency make a great difference to agricultural production. The correct utilization and residue of pesticides have always been important issues of concern, and residual pesticides can accumulate and pass through the environment and food cycle, resulting in safety and health hazards to humans and animals. In particular, current detection methods are often characterized by complex operations or low sensitivity.

Fluorescent Dye-Doped Brightening Polymer-Stabilized Bistable Cholesteric Liquid Crystal Films.

Brightening polymer-stabilized bistable cholesteric liquid crystal (PSBCLC) films with doped fluorescent dyes were prepared using the polymerization-induced phase separation (PIPS) method. The transmittance performance behavior of these films in both states (focal conic and planar) and absorbance change in multiple dye concentrations were studied using a UV/VIS/NIR spectrophotometer. The change occurring in dye dispersion morphology with different concentrations was obtained by means of the polarizing optical microscope.

Effect of Electrospinning Network Instead of Polymer Network on the Properties of PDLCs.

In this study, polymer-dispersed liquid crystal (PDLC) membranes were prepared by combining prepolymer, liquid crystal, and nanofiber mesh membranes under UV irradiation. EM, POM, and electro-optic curves were then used to examine the modified polymer network structure and the electro-optical properties of these samples. As a result, the PDLCs with a specific amount of reticular nanofiber films had considerably improved electro-optical characteristics and antiaging capabilities.

Flexible graphene-based metamaterial sensor for highly sensitive detection of bovine serum albumin.

A graphene-based metamaterial sensor working in the terahertz spectrum is proposed, simulated, and experimentally verified by measuring bovine serum albumin (BSA). Flexible, low-cost polyimide (PI) is used as the substrate, and aluminum with periodic square rings is chosen as the metal layer. Furthermore, the introduction of the graphene monolayer interacts with the molecules through - stacking, resulting in the highly sensitive detection of BSA by calculating the amplitude changes at the resonance frequency.

Slot hybrid-core waveguides for temperature-independent integrated optical sensors.

We propose a novel type of waveguides, called the slot hybrid-core waveguides (HCWs), for temperature-independent integrated optical sensors. The HCWs are composed of different core materials having the opposite thermo-optic coefficients (TOCs) and, therefore, are immune to temperature variations. On this basis, slot HCWs are proposed for the microring resonator-based optical sensors, enabling the sensors to simultaneously present high sensitivities and temperature independence.

Sensors for simultaneous measurement of temperature and humidity based on all-dielectric metamaterials.

In this study, a new type of sensors based on all-dielectric metamaterials that can measure temperature and relative humidity simultaneously was designed and theoretically analyzed in detail. The proposed metamaterial sensor consists of a quartz substrate in the bottom layer, polydimethylsiloxane (PDMS) in the middle layer, and a periodic silicon structure on the top layer. CST Studio Suite was used to determine the transmission spectrum of the metamaterials in the near-infrared band using finite integration, and two transmission dips were observed.

Smallholder Farmers Contribution to Food Production in Nigeria.

Several studies have shown that smallholder farmers produce most of the food in low-income and developing countries and form the backbone of the country's food supply. This study examines the extent these smallholder farmers in Nigeria can put the country on the path to self-sufficiency and ensure satiety for household food consumption through their local production. The study also examines food production and their resulting yield based on crop production and harvested area, as well as the percentage of crops produced for food or other purposes.

Cold Chain Food and COVID-19 Transmission Risk: From the Perspective of Consumption and Trade.

Since the outbreak of the coronavirus disease 2019 (COVID-19), political and academic circles have focused significant attention on stopping the chain of COVID-19 transmission. In particular outbreaks related to cold chain food (CCF) have been reported, and there remains a possibility that CCF can be a carrier. Based on CCF consumption and trade matrix data, here, the "source" of COVID-19 transmission through CCF was analyzed using a complex network analysis method, informing the construction of a risk assessment model reflecting internal and external transmission dynamics.

Broadband terahertz metamaterial absorber: design and fabrication.

We proposed and experimentally demonstrated a broadband terahertz (THz) metamaterial absorber based on a symmetrical L-shaped metallic resonator. The absorber structure produces two absorption peaks at 0.491 and 0.

Optical Fiber Based Mach-Zehnder Interferometer for APES Detection.

A 3-aminopropyl-triethoxysilane (APES) fiber-optic sensor based on a Mach-Zehnder interferometer (MZI) was demonstrated. The MZI was constructed with a core-offset fusion single mode fiber (SMF) structure with a length of 3.0 cm.

All-metal terahertz metamaterial biosensor for protein detection.

In this paper, a terahertz (THz) biosensor based on all-metal metamaterial is theoretically investigated and experimentally verified. This THz metamaterial biosensor uses stainless steel materials that are manufactured via laser-drilling technology. The simulation results show that the maximum refractive index sensitivity and the figure of merit of this metamaterial sensor are 294.

Prodrug-based nano-delivery strategy to improve the antitumor ability of carboplatin and .

Chemotherapy plays a major role in the treatment of cancer, but it still has great limitations in anti-tumor effect. Carboplatin (CAR) is the first-line drug in the treatment of non-small cell lung cancer, but the therapeutic effect is demonstrated weak. Therefore, we modified CAR with hexadecyl chain and polyethylene glycol, so as to realize its liposolubility and PEGylation.

Risk of Global External Cereals Supply under the Background of the COVID-19 Pandemic: Based on the Perspective of Trade Network.

International food trade is an integral part of the food system, and the COVID-19 pandemic has exposed the fragility of external food supplies. Based on the perspective of cereals trade networks (CTN), the pandemic risk is combined with the trade intensity between countries, and an assessment model of cereals external supply risk is constructed that includes external dependence index (EDI), import concentration, and risk of COVID-19 from import countries index (RICI). The results show that: (1) the global main CTN have typical scale-free characteristics, and seven communities are detected under the influence of the core countries; (2) about 60%, 50%, and 70% of countries face risks of medium and above (high and very high) external dependence, concentration of imports, and COVID-19 in the country of origin, respectively.

High sensitivity temperature sensor based on a side-hole fiber.

This paper proposes a temperature sensor based on a side-hole fiber (SHF). The sensor is formed by single-mode fiber (SMF)-coreless fiber (CLF)-SHF-CLF-SMF fusion splicing. The SHF adopts the dislocation fusion splicing method to ensure that one air hole is exposed.

Design and Fabrication of a Triple-Band Terahertz Metamaterial Absorber.

We presented and manufactured a triple-band terahertz (THz) metamaterial absorber with three concentric square ring metallic resonators, a polyethylene terephthalate (PET) layer, and a metallic substrate. The simulation results demonstrate that the absorptivity of 99.5%, 86.

Beta-elemene inhibits differentiated thyroid carcinoma metastasis by reducing cellular proliferation, metabolism and invasion ability.

Background: Accelerated glycolysis is a characteristic of carcinoma. The herb-derived compound, beta (β)-elemene, has shown promising anticancer effects against various tumors by inhibiting aerobic glycolysis. However, its activity against thyroid carcinoma and the mechanism is still unknown.

Tunable broadband all-silicon terahertz absorber based on a simple metamaterial structure.

We propose and demonstrate a modulatable all-silicon terahertz absorber based on a cylindrical metamaterial structure. Broadband absorption is obtained from 0.86 to 2.

Microfluidic flow direction and rate vector sensor based on a partially gold-coated TFBG.

In microfluidic chips applications, the monitoring of the rate and the direction of a microfluidic flow is very important. Here, we demonstrate a liquid flow rate and a direction sensor using a partially gold-coated tilted fiber Bragg grating (TFBG) as the sensing element. Wavelength shifts and amplitude changes of the TFBG transmission resonances in the near infrared reveal the direction of the liquid flowing along the fiber axis in the vicinity of the TFBG due to a nanoscale gold layer over part of the TFBG.

Analogue of electromagnetically induced transparency with high-Q factor in metal-dielectric metamaterials based on bright-bright mode coupling.

Based on bright-bright mode coupling, we numerically demonstrated the analogue of electromagnetically induced transparency (EIT) with a high quality factor (Q) in a stacked metal-dielectric metamaterial (MM) in the near-infrared regime. The optical coupling between a high-Q toroidal dipole mode supported by a silicon rod array and a low-Q dipole mode supported by a silver strip array was investigated from the near-field to the far-field regimes. We realized and significantly enhanced the long-range coupling between the two resonance modes through the MM-induced Fabry-Pérot (FP) effect.

Experimental Demonstration of Electromagnetically Induced Transparency in a Conductively Coupled Flexible Metamaterial with Cheap Aluminum Foil.

We propose a conductively coupled terahertz metallic metamaterial exhibiting analog of electromagnetically induced transparency (EIT), in which the bright and dark mode antennae interact via surface currents rather than near-field coupling. Aluminum foil, which is very cheap and often used in food package, is used to fabricate our metamaterials. Thus, our metamaterials are also flexible metamaterials.

Reduction of non-uniformity for a 16 × 16 arrayed waveguide grating router based on silica waveguides.

Here, a newly designed 16×16 cyclic arrayed waveguide grating router, capable of achieving loss uniformity across the whole free spectral range (FSR), is fabricated and experimentally demonstrated. This device is based on commonly used silica waveguides, which are compatible with basic planar lightwave circuit technology. The design, simulation, and experimental verification of the proposed method are presented, with the experimental results showing that the loss non-uniformity of FSR reduced from 2.

Spectrometer based on parallel-plate waveguides utilizing abnormal transmission.

We designed a new, simple device based on parallel-plate waveguides (PPWGs) utilizing abnormal transmission to achieve the analogous function of a terahertz spectrometer. The phase gradient of the PPWGs is π/mm, and the designed wavelength is 0.3 THz.

Thermal stability of optical fiber metal organic framework based on graphene oxide and nickel and its hydrogen adsorption application.

The electrochemistry (EC) method was used to synthesize graphene oxide-nickel (GO-Ni) metal organic framework (MOF) that has the thickness of μm-level. The MOF's thermal stability and hydrogen adsorption and desorption capacity were measured by using an optical fiber Mach-Zehnder interferometer (MZI) sensor. This MZI was fabricated by core-offset fusion splicing one section of single mode fiber (SMF) between two SMFs.