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The high-carbohydrate, low-fat, low-protein (HC-LFP) and low-carbohydrate, high-fat, high-protein (LC-HFP) diets are the main dietary patterns worldwide. The influence of dietary patterns on bioavailable metals, gut microbes, and their interaction is still unknown. A biomimetic digestive tract with full functions is constructed to transform the diets into chyme, and the gut microbes are cultured with the corresponding chyme. The diet species-specificity in bioavailable metal content and the positive and negative correlations between bioavailable metals and microbial reproductions are disclosed. The safe dosage and maximum consumption are 369.5 and 858.6 g/d and 268.6 and 3119.0 g/d for LC-HFP and HC-LFP, respectively. When replacing HC-LFP with LC-HFP for 21 days, the bioavailability of Fe and Cr is increased 83.2% and 268.4%, respectively; the reproductions of harmful and benefical microbes are significantly increased and decreased. The prevalences of obesity, inflammation, septicemia, and cancer are increased, and then the risk of dietary pattern shift is disclosed.

Ultra-peripheral heavy-ion collisions (UPCs) offer unique opportunities to study processes under strong electromagnetic fields. In these collisions, highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon fluxes. The exchange of photons can induce photonuclear and two-photon interactions and excite ions. This excitation of the ions results in Coulomb dissociation with the emission of photons, neutrons, and other particles. Additionally, the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ions. Consequently, the two colliding ions experience an electromagnetic force that pushes them in opposite directions, causing a back-to-back correlation in the emitted neutrons. Using a Monte Carlo simulation, we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs, which would provide a clear means to study strong electromagnetic fields and their effects.

The relativistic heavy-ion collisions create both hot quark–gluon matter and strong magnetic fields, and provide an arena to study the interplay between quantum chromodynamics and quantum electrodynamics. In recent years, it has been shown that such an interplay can generate a number of interesting quantum phenomena in hadronic and quark–gluon matter. In this short review, we first discuss some properties of the magnetic fields in heavy-ion collisions and then give an overview of the magnetic field-induced novel quantum effects. In particular, we focus on the magnetic effect on the heavy flavor mesons, the heavy-quark transports, and the phenomena closely related to chiral anomaly.

We derive a Cooper-Frye type spin polarization formula for Dirac fermions at local thermal equilibrium described by a grand canonical ensemble specified by temperature, fluid velocity, chemical potential, and spin potential. We discuss the physical meaning of different contributions to spin polarization and compare them with previous work. The present formula provides machinery to convert the spin potential computed in, e.g., relativistic spin hydrodynamics to the spin polarization observable in, e.g., heavy-ion collisions.

An ultra-compact electro-optical (EO) switch based on long-range air-hole assisted subwavelength waveguides with a high extinction ratio, low insertion loss, and high operation speed is proposed and investigated, both analytically and numerically. The switching characteristic of the EO switch also is addressed at three different resonant wavelengths. A modulation depth of 26.8 dB and a small active region of 1.04  μm^2 at the wavelength of 1.597 μm can be achieved. Such an active TE-mode device based on subwavelength waveguides provides a promising approach for highly effective EO switches, and is beneficial for high-density photonic integration.

A novel air-hole assisted metaldielectricmetal (MDM) waveguide has been proposed and numerically demonstrated. It has excellent characters including subwavelength mode confinement, chip-scale long propagation length, highly efficient direct bends with compact footprints, and high waveguide isolation with tiny center-to-center separation at the wavelength of 1.55 μm. To prove that the hybrid waveguide could be an ideal candidate for large-scale photonic integration, its characters are all compared with the silicon, photonic crystal, surface plasmon polariton based waveguides.

In order to monitoring the health of the structure, a quasi-distributed fiber Bragg grating (FBG) interrogator based on two-channel theory of the arrayed waveguide grating (AWG) demultiplexer is presented. As is known, a slightly change of the temperature or strain or other related parameters applied on the FBG will lead to a shift of the Bragg wavelength of the FBG, which makes sense on the precisely temperature and strain monitoring of structures, including viaduct bridges, towers, railway, skyscraper, etc. It can be interrogated by the relative intensity of two-adjacent-channel of the AWG-based demultiplexer, which offers a low-cost, high sensitivity for the interrogation of FBG distributed sensors.

A simple fiber-optic sensor based on Fabry–Perot interference for refractive index measurement of optical glass is investigated both theoretically and experimentally. A broadband light source is coupled into an extrinsic fiber Fabry–Perot cavity formed by the surfaces of a sensing fiber end and the measured sample. The interference signals from the cavity are reflected back into the same fiber. The refractive index of the sample can be obtained by measuring the contrast of the interference fringes. The experimental data meet with the theoretical values very well. The proposed technique is a new method for glass refractive index measurement with a simple, solid, and compact structure.

Characteristics of double-sided teeth-shaped nanoplasmonic waveguide filters are systematically investigated. It is found that the asymmetrical double-sided teeth-shaped waveguide structure can realize the function of a two-wavelength filter, and its two wavelengths are linear with the depths of the two-sided teeth, respectively. It is also found that a staggered double-sided teeth-shaped structure exahibits a wide and sharp bandgap. Double-sided teeth-shaped filters are of ultracompact size, in the length of a few hundred nanometers. The finite-difference time-domain method is employed in the simulations. Our results may open a way to construct nanoscale waveguide filters for high-density nanoplasmonic integration circuits.

We report a compact flat-top beam shaper fabricated by laser-assisted chemical etching upon an ion-exchanged high-energy-beam-sensitive glass. The beam shaper combines a phase filter element and a focusing lens element into a single diffractive optical element with a quasi-continuous surface relief profile. The fabrication takes advantage of the laser generation of gray-level patterns and one-step etching that are effective especially for such beam shaper fabrication. The demonstrated beam shaper with good flatness and edge features has an energy efficiency of 82. © 1999 Society of Photo-Optical Instrumentation Engineers.

The diffraction-limited spot size limits the optical disk storage capacity and microscopic resolution. We describe a technique to shape a focused Gaussian beam into a superresolving beam by using a diffractive optical element fabricated by laser-assisted chemical etching. The focused shaped beam has a smaller width and a longer depth of focus than a similarly focused Gaussian beam. Using the diffraction-limited shaped beam along with threshold writing, we achieved a written pit size of less than 0.33 µm at a 695-nm laser wavelength, compared with a 0.7-µm focused Gaussian spot size (full width at e^-2 of the peak) with the same focusing lens. The energy conversion efficiency for the beam shaping was ∼81%.

In this work, the lithium-storage performance and mechanism of a designed (Ni0.5Co0.5)9S8@NC hollow nanocube composite as a rechargeable lithium-ion battery (LIB) anode are investigated. The nanocomposite is composed of a bimetallic sulfide (Ni0.5Co0.5)9S8core and a surrounding nitrogen-doped carbon shell. It displays a superior electrochemical reactivity with an appealing specific capacity of 724 mAh g–1at a specific current of 0.5 A g–1cycled 80 times, as well as attractive stability and rate capability. The quantitative kinetic analysis reveals that the advanced lithium-storage performance is partly derived from the pseudocapacitive contributions. In situX-ray diffraction (XRD) demonstrates the formation of Ni, Co, and Li2S in the conversion reaction during the initial cycling. Ex situtransmission electron microscopy (TEM) and scanning electron microscopy (SEM) demonstrate the volume expansion of the core (Ni0.5Co0.5)9S8active material with the essential preservation of the complete (Ni0.5Co0.5)9S8@NC hollow nanocube structure during repeating cycling. Namely, the synergistic effect of the N-doped carbon coating, the rigid hollow nanostructure, and the multiple-electron-transfer conversion reaction of the bimetallic sulfide contributes to the superior lithium-storage performance of the nanocomposite.

A simple fiber sensor for magnetic field measurement based on nanoparticle Fe_3O_4 magnetic fluid and relative Fresnel reflection is presented. The sensor includes only a light source, three couplers, two photodetectors, and two fiber sensing ends. Magnetic fields at different concentrations of magnetic fluid are measured. Magnetic fluid with high concentration can be used for the measurement of weak magnetic fields, while low concentration fluid is used for the measurement of strong magnetic fields. The temperature dependence of the sensor is also addressed.

A novel nanometeric plasmonic filter in a tooth-shaped metal-insulator-metal waveguide is proposed and demonstrated numerically. An analytic model based on the scattering matrix method is given. The result reveals that the single tooth-shaped filter has a wavelength-filtering characteristic and an ultracompact size in the length of a few hundred nanometers, compared to gratinglike surface plasmon polariton (SPP) filters. Both analytic and simulation results show that the wavelength of the trough of the transmission has linear and nonlinear relationships with the tooth depth and the tooth width, respectively. The waveguide filter could be utilized to develop ultracompact photonic filters for high integration.

We investigate the dynamics of optical matter creation and annihilation in a colloidal liquid that was employed to construct an all-optical switch. It is revealed that the switching-on process can be characterized by the Fermi-Dirac distribution function, while the switching-off process can be described by a steady state followed by a single exponential decay. The phase transition times exhibit a strong dependence on trapping power. With an increasing trapping power, while the switching-on time decreases rapidly, the switch-off time increases significantly, indicating the effects of optical binding and van der Waals force on the lifetime of the optical matter.

An all-metal absorber consisting of an L-shaped stripe with two vertical pillars is constructed and investigated for triple-band absorption. The nanostructure reveals distinct absorption properties at resonant wavelengths selected by the polarization of incident waves. It achieves single-band absorptivity of 98.5% at 5.198 ?m for 135° linearly polarized wave and dual-band absorptivity of 91.5% and 99.4% at 3.058 ?m and 3.887 ?m respectively for 45° linear polarization. We interpret the physical mechanism by using the charge-current multipolar expansion framework, which shows that the excitation of two transverse magnetic dipoles and a non-radiating anapole are responsible for these absorption resonances.

A flow injection method has been developed for the direct determination of free available Pb(II). The method is based on the chemical sorption of Pb(II), from pH7 solutions, on a column packed of chelating resin. The retained complex was afterwards eluted with hydrochloric acid followed by hydride generation with reduction by tetrahydroborate. The preconcentration system proposed in this paper allows the elimination of great part of the saline content in the sample. A thorough scrutiny was made for chemical variables and FI parameters. With a sampling volume of 10.5 mL, quantitative retention of Pb (II) was obtained, along with an enrichment factor of 40 and a sampling frequency of 15 h−1. The detection limit, defined as 3 times the blank standard deviation (3σ), was 0.0031 ngml−1. The precision was characterized by an RSD value of 3.78% (at the 4 ng⋅ml−1 level, n=11). The developed method has been applied to the determination of trace Pb in three standard reference materials. Accuracy was assessed through comparing the results with the accepted values.