Simultaneous Circular Dichroism and Wavefront Manipulation with Generalized Pancharatnam-Berry Phase Metasurfaces.

Simultaneous circular dichroism and wavefront manipulation have gained considerable attention in various applications, such as chiroptical spectroscopy, chiral imaging, sorting and detection of enantiomers, and quantum optics, which can improve the miniaturization and integration of the optical system. Typically, structures with n-fold rotational symmetry (n ≥ 3) are used to improve circular dichroism, as they induce stronger interactions between the electric and magnetic fields. However, manipulating the wavefront with these structures remains challenging because they are commonly considered isotropic and lack a geometric phase response in linear optics. Here, we propose and experimentally demonstrate an approach to achieve simultaneous circular dichroism (with a maximum value of ∼0.62) and wavefront manipulation using a plasmonic metasurface made up of C3 Archimedes spiral nanostructures. The circular dichroism arises from the magnetic dipole-dipole resonance and strong interactions between adjacent meta-atoms. As a proof of concept, two metadevices are fabricated and characterized in the near-infrared regime. This configuration possesses the potential for future applications in photodetection, chiroptical spectroscopy, and the customization of linear and nonlinear optical responses.

Investigating fungal community characteristics in co-composted cotton stalk and various livestock manure products.

Agricultural wastes, comprising cotton straw and livestock manure, can be effectively managed through aerobic co-composting. Nevertheless, the quality and microbial characteristics of co-composting products from different sources remain unclear. Therefore, this study utilized livestock manure from various sources in Xinjiang, China, including herbivorous sheep manure (G), omnivorous pigeon manure (Y), and pigeon-sheep mixture (GY) alongside cotton stalks, for a 40-day co-composting process. We monitored physicochemical changes, assessed compost characteristics, and investigated fungal community. The results indicate that all three composts met established composting criteria, with compost G exhibiting the fastest microbial growth and achieving the highest quality. Ascomycota emerged as the predominant taxon in three compost products. Remarkably, at the genus level, the biomarker species for G, Y, and GY are Petromyces and Cordyceps, Neurospora, and Neosartorya, respectively. Microorganisms play a pivotal role in organic matter degradation, impacting nutrient composition, demonstrating significant potential for the decomposition and transformation of compost components. Redundancy analysis indicates that potassium, total organic carbon, and C:N are key factors influencing fungal communities. This study elucidates organic matter degradation in co-composting straw and livestock manure diverse sources, optimizing treatment for efficient agricultural waste utilization and sustainable practices.

Recovery of Chlorosilane Residual Liquid to Prepare Nano-Silica via the Reverse Micro-Emulsion Process.

In this paper, nano-silica particles were prepared from chlorosilane residue liquid using an inverse micro-emulsions system formed from octylphenyl polyoxyethylene ether (TX-100)/n-hexanol/cyclohexane/ammonia. The influence of different reaction conditions on the morphology, particle size, and dispersion of nano-silica particles was investigated via single-factor analysis. When the concentration of chlorosilane residue liquid (0.08 mol/L), hydrophile-lipophilic-balance (HLB) values (10.50), and the concentration of ammonia (0.58 mol/L) were under suitable conditions, the nano-silica particles had a more uniform morphology, smaller particle size, and better dispersion, while the size of the nano-silica particles gradually increased with the increase in the molar ratio of water to surfactant (ω). The prepared nano-silica was characterized through XRD, FT-IR, N2 adsorption/desorption experiments, and TG-DSC analysis. The results showed that the prepared nano-silica was amorphous mesoporous silica, and that the BET specific surface area was 850.5 m2/g. It also had good thermal stability. When the temperature exceeded 1140 °C, the nano-silica underwent a phase transition from an amorphous form to crystalline. This method not only promoted the sustainable development of the polysilicon industry, it also provided new ideas for the protection of the ecological environment, the preparation of environmental functional materials, and the recycling of resources and energy.

Novel Method for Image-Based Quantified In Situ Transmission Electron Microscope Nanoindentation with High Spatial and Temporal Resolutions.

In situ TEM mechanical stages based on micro-electromechanical systems (MEMS) have developed rapidly over recent decades. However, image-based quantification of MEMS mechanical stages suffers from the trade-off between spatial and temporal resolutions. Here, by taking in situ TEM nanoindentation as an example, we developed a novel method for image-based quantified in situ TEM mechanical tests with both high spatial and temporal resolutions. A reference beam was introduced to the close vicinity of the indenter-sample region. By arranging the indenter, the sample, and the reference beam in a micron-sized area, the indentation depth and load can be directly and dynamically acquired from the relative motion of markers on the three components, while observing the indentation process at a relatively high magnification. No alteration of viewing area is involved throughout the process. Therefore, no deformation events will be missed, and the collection rate of quantification data can be raised significantly.

Full-space wavefront manipulation enabled by asymmetric photonic spin-orbit interactions.

Optical metasurfaces empower complete wavefront manipulation of electromagnetic waves and have been found in extensive applications, whereas most of them work in either transmission or reflection space. Here, we demonstrate that two independent and arbitrary phase profiles in transmission and reflection spaces could be produced by a monolayer all-dielectric metasurface based on the asymmetric photonic spin-orbit interactions, realizing full-space wavefront independent manipulation. Furthermore, the supercell-based non-local approach is employed to suppress crosstalk between adjacent nanopillars in one supercell for broadband and high-efficiency wavefront manipulation in full space. Compared with the conventional unit cell-based local approach, such a method could improve efficiency about 10%. As a proof of concept, two metadevices are designed, in which the maximum diffraction efficiencies are ∼95.53%/∼74.07% within the wavelength range of 1500-1600 nm in reflection/transmission space under circularly polarized light incidence. This configuration may offer an efficient way for 2π-space holographic imaging, augmented reality, virtual reality technologies, three-dimensional imaging, and so forth.

Broadband and high-efficiency photonic spin-Hall effect with all-metallic metasurfaces.

In this paper, all-metallic reflective metasurfaces comprising S-shape streamline structures are proposed to achieve the photonic spin-Hall effect with average cross-polarization conversion efficiency exceeding ∼84% in the range of 8-14 µm. By comparing with all-metallic nanobricks, it is demonstrated that the electric field coupling could be enhanced by constructing a similar split ring resonator between adjacent unit elements to further improve its efficiency and bandwidth. As a proof of concept, the photonic spin Hall effect and spin-to-orbit angular momentum conversion could be observed by two metadevices with the maximum diffraction efficiency of ∼95.7%. Such an all-metallic configuration may provide a platform for various high-efficiency electromagnetic components, catenary optics, and practical applications.

Simultaneous polarization filtering and wavefront shaping enabled by localized polarization-selective interference.

The ability of simultaneous polarization filter and wavefront shaping is very important for many applications, especially for polarization imaging. However, traditional methods rely on complex combinations of bulky optical components, which not only hinder the miniaturization and integration but also reduce the efficiency and imaging quality. Metasurfaces have shown extraordinary electromagnetic properties to manipulate the amplitude, polarization, and wavefront. Unfortunately, multi-layer metasurfaces with complex fabrication are often required to realize complex functions. Here, a platform of monolayer all-dielectric metasurfaces is proposed to simultaneously achieve polarization filtering and wavefront shaping, based on the principle of local polarization-selective constructive or destructive interference. The transmission efficiency surpassing 0.75 and polarization extinction ratio exceeding 11.6 dB are achieved by the proposed metasurface at the wavelength of 10.6 µm. These results are comparable to those of multi-layer metasurfaces. Considering these good performances, this work may prove new ideas for the generation of complex optical field and find wide applications in polarization imaging.

Rice protein suppresses ROS generation and stimulates antioxidant gene expression via Nrf2 activation in adult rats.

To elucidate the effects of rice protein on the detoxification and antioxidant defense via the Nuclear factor erythroid 2-related factor 2 (Nrf2) pathway, adult rats were fed casein and rice protein under cholesterol-free and -enriched dietary conditions. Nrf2 proteins and gene expressions were stimulated by rice proteins with respect to caseins accompanied by up-regulating the expression of gene encoding antioxidant and phase II detoxification in the rice protein groups. In the liver, compared with caseins, rice proteins significantly increased hepatic contents of reduced glutathione (GSH) and mRNA levels of glutamate cysteine ligase catalytic subunit (GCLC), glutamate cysteine ligase modulatory subunit (GCLM), glutathione S-transferase (GST), heme oxygenase 1 (HO-1) and NAD(P)H: quinone oxidoreductase 1 (NQO1), whereas hepatic accumulations of reactive oxygen species (ROS) and oxidized glutathione (GSSG) were markedly depressed in adult rats fed rice proteins. The present study demonstrates the endogenous antioxidant potential of rice proteins via mechanism through which Nrf2 activation plays an essential role in inducing Phase II antioxidants/detoxification enzymes and preventing ROS generation. This novel antioxidative function of rice protein is independent of dietary cholesterol during in adult rats.

Revealing ultralarge and localized elastic lattice strains in Nb nanowires embedded in NiTi matrix.

Freestanding nanowires have been found to exhibit ultra-large elastic strains (4 to 7%) and ultra-high strengths, but exploiting their intrinsic superior mechanical properties in bulk forms has proven to be difficult. A recent study has demonstrated that ultra-large elastic strains of ~6% can be achieved in Nb nanowires embedded in a NiTi matrix, on the principle of lattice strain matching. To verify this hypothesis, this study investigated the elastic deformation behavior of a Nb nanowire embedded in NiTi matrix by means of in situ transmission electron microscopic measurement during tensile deformation. The experimental work revealed that ultra-large local elastic lattice strains of up to 8% are induced in the Nb nanowire in regions adjacent to stress-induced martensite domains in the NiTi matrix, whilst other parts of the nanowires exhibit much reduced lattice strains when adjacent to the untransformed austenite in the NiTi matrix. These observations provide a direct evidence of the proposed mechanism of lattice strain matching, thus a novel approach to designing nanocomposites of superior mechanical properties.

Antioxidant capacity responsible for a hypocholesterolemia is independent of dietary cholesterol in adult rats fed rice protein.

Dietary cholesterol and aging are major risk factors to accelerate oxidation process for developing hypercholesterolemia. The major aim of this study is to elucidate the effects of rice protein on cholesterol level and oxidative stress in adult rats fed with and without cholesterol. After 2 weeks of feeding, hepatic and plasma contents of cholesterol, reduced glutathione (GSH), oxidized glutathione (GSSG), malondialdehyde (MDA) and protein carbonyl (PCO) were measured. In liver, total antioxidative capacity (T-AOC), activities of antioxidant enzymes (total superoxide dismutase, T-SOD; catalase, CAT), glutathione metabolizing enzyme activities and gene expression levels (γ-glutamylcysteine synthetase, γ-GCS; glutathione reductase, GR; glutathione peroxidase, GPx) were determined. Under cholesterol-free/enriched dietary condition, T-AOC, activities of T-SOD and CAT, glutathione metabolism related enzymes' activities and mRNA levels (γ-GCS, GR and GPx) were effectively stimulated by rice proteins as compared to caseins. Compared with caseins, rice proteins significantly increased hepatic and plasma GSH contents, whereas hepatic and plasma accumulations of MDA, PCO and GSSG were significantly reduced by rice protein-feedings. As a result, the marked reductions of cholesterol in the plasma and in the liver were observed in adult rats fed rice proteins with and without cholesterol. The present study demonstrates that the hypocholesterolemic effect of rice protein is attributable to inducing antioxidative response and depressing oxidative damage in adult rats fed cholesterol-free/enriched diets. Results suggest that the antioxidant capability involved in the hypocholesterolemic action exerted by rice protein is independent of dietary cholesterol during adult period.