A Region-Monitoring-Type Slitless Imaging Spectrometer.

In modern scientific practice, it is necessary to consistently observe predetermined zones, with the expectation of detecting and identifying emerging targets or events inside such areas. This research presents an innovative imaging spectrometer system for the continuous monitoring of specific areas. This study begins by providing detailed information on the features and optical structure of the constructed instrument. This is then followed by simulations using optical design tools. The device has an F-number of 5, a focal length of 100 mm, a field of view of 3 × 7, and a wavelength range spanning from 400 nm to 600 nm. The optical path diagram demonstrates that the system's dispersion and imaging pictures can be distinguished, hence fulfilling the system's specifications. Furthermore, the utilization of a Modulation Transfer Function (MTF) graph has substantiated that the image quality indeed satisfies the specified criteria. To evaluate the instrument's performance in the spectrum observation of fixed regions, a region-monitoring-type slitless imaging spectrometer was built. The equipment has the capability to identify a specific region and rapidly capture the spectra of objects or events that are present inside that region. The spectral data were collected effectively by the implementation of image processing techniques on the captured photos. The correlation coefficient between these data and the reference data was 0.9226, showing that the device successfully measured the target's spectrum. Therefore, the instrument that was created successfully demonstrated its ability to capture images of the observed areas and collect spectral data from the targets located within those regions.

Partitionable High-Efficiency Multilayer Diffractive Optical Neural Network.

A partitionable adaptive multilayer diffractive optical neural network is constructed to address setup issues in multilayer diffractive optical neural network systems and the difficulty of flexibly changing the number of layers and input data size. When the diffractive devices are partitioned properly, a multilayer diffractive optical neural network can be constructed quickly and flexibly without readjusting the optical path, and the number of optical devices, which increases linearly with the number of network layers, can be avoided while preventing the energy loss during propagation where the beam energy decays exponentially with the number of layers. This architecture can be extended to construct distinct optical neural networks for different diffraction devices in various spectral bands. The accuracy values of 89.1% and 81.0% are experimentally evaluated for MNIST database and MNIST fashion database and show that the classification performance of the proposed optical neural network reaches state-of-the-art levels.

The Photocatalysis-Enhanced TiO2@HPAN Membrane with High TiO2 Surface Content for Highly Effective Removal of Cationic Dyes.

The elimination of dye pollutants from wastewater is a significant concern that has prompted extensive research into the development of highly efficient photocatalytic membranes. A novel method was proposed to prepare photocatalysis-enhanced poly(acrylonitrile-methyl acrylate) (PAN-based) membranes in this study. In detail, the blended membrane containing SiO2@TiO2 nanoparticles with a shell-core structure was first prepared via thermal-induced phase separation. The SiO2 nanoshells were dissolved, and the released TiO2 nanoparticles migrated to the membrane surface during a simple hydrolysis process, which prevents the TiO2 nanoparticles from directly contacting or interacting with the polymer matrix. The hydrogen bonds bind the exposed TiO2 with the PAN membrane surface, resulting in the formation of the TiO2@HPAN hybrid membrane. The photocatalytic efficiency of the TiO2@HPAN membrane doubled compared with that of nonhydrolyzed membranes. In the presence of UV light, the hybrid membrane can degrade 99.8% of methylene blue solution in less than 2 h, compared to only 86.1% for the blended membranes. Further, the TiO2@HPAN membrane showed excellent photocatalytic activity for cationic dyes due to electrostatic attraction. Moreover, the high-flux recovery rate and recycling stability of the TiO2@HPAN membrane lead to an excellent antifouling property. The facile preparation method proposed in this work shows extraordinary potential for the development of highly efficient selective photocatalytic materials for cationic dyes to be used in wastewater treatment applications.

Molecular mechanisms associated with oxidative damage in the mouse testis induced by LaCl3.

China is the world's largest rare earth producer and exporter, previous studies have shown that rare earth elements can cause oxidative damage in animal testis. However, the molecular mechanisms underlying these observations have yet to be elucidated. In this paper, male mice were fed with different doses (10, 20, and 40 mg/kg BW) of LaCl3 for 90 consecutive days, regulatory role of nuclear factor erythroid-2 related factor 2 (Nrf-2)/antioxidant response element (ARE) pathway in testicular oxidative stress induced by LaCl3 were investigated. Analysis showed that LaCl3 exposure could lead to severe testicular pathological changes and apoptosis in spermatogenic cells, it up-regulated the peroxidation of lipids, proteins and DNA, and induced the excessive levels of reactive oxygen species (ROS) production in mouse testis, reduced the activities of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and glutathione S epoxide transferase (GST) as well as the glutathione (GSH) content. Furthermore, exposure to LaCl3 also downregulated the expression of Nrf2 and its target gene products, including heme oxygenase 1 (HO-1), glutamate-cysteine ligase catalytic subunit (GCLC), NAD(P)H dehydrogenase [quinine] 1(NQO1), protein kinase C (PKC), and phosphatidylinositol 3-kinase (PI3K), but upregulated the expression of Kelch-like ECH-related protein 1 (Keap1) in damaged mouse testes. Collectively, our data imply that the oxidative damage induced by LaCl3 in testis was related to inhibition of the Nrf-2/AREs pathway activation.

Optical SAR data processing configuration with simultaneous azimuth and range matching filtering.

The real-time processing of synthetic aperture radar (SAR) data has a high requirement for the processor, which is a difficult problem in SAR real-time processing. With the rapid development of optoelectronic devices, traditional electrical SAR data processing can be converted into optoelectronic processing to improve the processing speed. In this paper, a new type of optical device is proposed to improve the processing speed of SAR data. With the help of a spatial light modulator (SLM), the initial SAR signal and matched filter function are loaded on the input plane and spectrum plane of the 4f system, respectively. Using an optical lens with the function of the Fourier transform, the Fourier transform and inverse Fourier transform of the SAR signal are carried out to realize the fast imaging of SAR. In theory, the processing speed of SAR data is the speed of light. Compared with traditional methods such as the range-Doppler (RD) algorithm, it is no longer necessary to carry out a one-dimensional Fourier transform but to carry out matching filtering for the azimuth and range of the spectrum plane of 4f system at the same time. In this way, it is not necessary to introduce a cylindrical lens, only a spherical lens is needed to realize the Fourier transform imaging of SAR. Finally, a two-dimensional SAR processing optical system is built to obtain the SAR image in real time.

Long-Distance Sub-Diffraction High-Resolution Imaging Using Sparse Sampling.

How to perform imaging beyond the diffraction limit has always been an essential subject for the research of optical systems. One effective way to achieve this purpose is Fourier ptychography, which has been widely used in microscopic imaging. However, microscopic imaging measurement technology cannot be directly extended to imaging macro objects at long distances. In this paper, a reconstruction algorithm is proposed to solve the need for oversampling low-resolution images, and it is successfully applied to macroscopic imaging. Compared with the traditional FP technology, the proposed sub-sampling method can significantly reduce the number of iterations in reconstruction. Experiments prove that the proposed method can reconstruct low-resolution images captured by the camera and achieve high-resolution imaging of long-range macroscopic objects.

A High Optical Throughput Spectral Imaging Technique Using Broadband Filters.

To address the miniaturization of the spectral imaging system required by a mounted platform and to overcome the low luminous flux caused by current spectroscopic technology, we propose a method for the multichannel measurement of spectra using a broadband filter in this work. The broadband filter is placed in front of a lens, and the spectral absorption characteristics of the broadband filter are used to achieve the modulation of the incident spectrum of the detection target and to establish a mathematical model for the detection of the target. The spectral and spatial information of the target can be obtained by acquiring data using a push-broom method and reconstructing the spectrum using the GCV-based Tikhonov regularization algorithm. In this work, we compare the accuracy of the reconstructed spectra using the least-squares method and the Tikhonov algorithm based on the L-curve. The effect of errors in the spectral modulation function on the accuracy of the reconstructed spectra is analyzed. We also analyze the effect of the number of overdetermined equations on the accuracy of the reconstructed spectra and consider the effect of detector noise on the spectral recovery. A comparison between the known data cubes and our simulation results shows that the spectral image quality based on broadband filter reduction is better, which validates the feasibility of the method. The proposed method of combining broadband filter-based spectroscopy with a panchromatic imaging process for measurement modulation rather than spectroscopic modulation provides a new approach to spectral imaging.

Bioinspired Superwettable Covalent Organic Framework Nanofibrous Composite Membrane with a Spindle-Knotted Structure for Highly Efficient Oil/Water Emulsion Separation.

Covalent organic frameworks (COFs) have attracted broad interest in a number of fields including gas access, catalysis, and ionic adsorption. However, owing to the low stability in water, the application of COFs in the field of oil/water separation is extensively impeded. In this paper, we synthesized COF-DhaTab/polyacrylonitrile (PAN) nanofibrous composite membranes with a bioinspired spindle-knotted structure via a facile blending electrospinning method. The COF-DhaTab/PAN composite membrane shows prewetting-induced superoleophobicity under water and superhydrophobicity under oil. It possesses outstanding rejection ratio (>99.9%), excellent antifouling performance, and ultrahigh oil/water mixture flux up to 4229.29 L/m2h even though driven only by gravity. Specifically, an extraordinary oil contact angle under water (152.3°) and a satisfied water contact angle under oil (153.7°) were offered by the composite membrane. These are mainly attributed to the spindle-knotted structures induced by COFs. To the best of our knowledge, the application of COF/PAN composite membrane in the field of oil/water separation has never been reported. It is an innovative approach for oily wastewater treatment and oil purification.

Direct Liquid Phase Exfoliation of Graphite to Produce Few-Layer Graphene by Microfluidization.

Graphene has attracted a great number of attentions due to the excellent physical and chemical properties. For the convenience of investigations and applications, it is crucial to produce the grapheme with high-quality and high-yield by an easy-obtained method. In this research, a promising method is demonstrated to produce a high-concentration few-layer graphene (FLG) dispersion by direct microfluidization in water/surfactant systems. The effects of surfactant selection, chamber pressure and microfluidization cycles on the graphitic material exfoliation efficiency are systematically studied. The FLG concentration and the quality of the as-prepared FLG were determined by a series of characterizations. The graphene dispersions, with an average lateral size of 0.6 µm and a few-layer structure, were stabilized by surfactants at a high concentration of up to 1.7 mg/mL and exhibited a relatively high quality (ID/IG = 0.07-0.56, C/O ~ 19.36) within a processing time of a few hours. This method should facilitate the mass production of high-quality graphene by liquid-phase exfoliation and promote the industrial application of graphene.

Fabrication of a PPS Microporous Membrane for Efficient Water-in-Oil Emulsion Separation.

Separation of emulsified water/oil mixtures is a worldwide concern. However, poor chemical and solvent resistance of general polymeric membranes limit these membranes for application in the separation process. In this study, a poly(phenylene sulfide) (PPS) porous membrane with a rough concave topographic feature was fabricated, which exhibited excellent superoleophilicity and under-oil superhydrophobicity. The membrane is capable of separating both surfactant-free and surfactant-stabilized emulsions with a high flux. All of the water contents of the treated oils were below 300 ppm. The excellent water resistance property and cycling performance support the PPS membrane displaying an excellent reusability. Additionally, this PPS membrane was also certified to be used in strong solvents for a long time. In conclusion, the successful application of the thermally induced phase separation (TIPS) method may provide a new approach to fabricate the PPS membrane and improve its properties, and the application of the PPS membrane to separate water-in-oil emulsions is promising in practical applications.

MnO2/MWCNTs Nanocomposites as Highly Efficient Catalyst for Indoor Formaldehyde Removal.

Formaldehyde (HCHO) is a main indoor pollutant that is capable of harming the health of residents. Here, we fabricated a novel MnO2/MWCNTs nanocomposite film for non-photocatalytic, room temperature removal of indoor HCHO. MnO2/MWCNTs nanocomposites with various amounts of a-MWCNTs, which were fabricated by a co-precipitation method, were assembled into composite films using vacuum filtration and solvent evaporation. Structural analysis confirms that MnO2 nanoparticles are homogeneously distributed on a-MWCNTs. The acetyl acetone method was used to characterize the catalytic activity of MnO2/MWCNTs nanocomposites. The results show that MnO2/MWCNTs composites with 30 wt% a-MWCNTs present the highest catalytic activity due to a highly active surface. The catalytic activity of MnO2/MWCNTs composite film was characterized in a glovebox at room temperature and showed good removal of HCHO. This study suggests that supporting catalysts on MWCNTs and then assembling them into fibers (1D), films (2D) or aerogels (3D) is a worthwhile approach to promote catalytic activity and prevent dust pollution.

Mussel-Inspired Polydopamine-Functionalized Graphene as a Conductive Adhesion Promoter and Protective Layer for Silver Nanowire Transparent Electrodes.

For the scalable fabrication of transparent electrodes and optoelectronic devices, excellent adhesion between the conductive films and the substrates is essential. In this work, a novel mussel-inspired polydopamine-functionalized graphene/silver nanowire hybrid nanomaterial for transparent electrodes was fabricated in a facile manner. Graphene oxide (GO) was functionalized and reduced by polydopamine while remaining stable in water without precipitation. It is shown that the polydopamine-functionalized GO (PFGO) film adhered to the substrate much more easily and more uniformly than the GO film. The PFGO film had a sheet resistance of ∼3.46 × 10(8) Ω/sq and a transparency of 78.2%, with excellent thermal and chemical stability; these characteristics are appropriate for antistatic coatings. Further reduced PFGO (RPFGO) as a conductive adhesion promoter and protective layer for the Ag nanowire (AgNW) significantly enhanced the adhesion force between AgNW networks and the substrate. The RPFGO-AgNW electrode was found to have a sheet resistance of 63 Ω/sq and a transparency of 70.5%. Moreover, the long-term stability of the RPFGO-AgNW electrode was greatly enhanced via the effective protection of the AgNW by RPFGO. These solution-processed antistatic coatings and electrodes have tremendous potential in the applications of optoelectronic devices as a result of their low production cost and facile processing.

Optimal design of tilt carrier frequency computer-generated holograms to measure aspherics.

Computer-generated holograms (CGHs) provide an approach to high-precision metrology of aspherics. A CGH is designed under the trade-off among size, mapping distortion, and line spacing. This paper describes an optimal design method based on the parametric model for tilt carrier frequency CGHs placed outside the interferometer focus points. Under the condition of retaining an admissible size and a tolerable mapping distortion, the optimal design method has two advantages: (1) separating the parasitic diffraction orders to improve the contrast of the interferograms and (2) achieving the largest line spacing to minimize sensitivity to fabrication errors. This optimal design method is applicable to common concave aspherical surfaces and illustrated with CGH design examples.

Covalent organic framework functionalized smart membranes with under-liquid dual superlyophobicity for efficient separation of oil/water emulsions.

The smart membrane with under-liquid dual superlyophobicity, which can achieve on-demand separation of oil/water emulsions only by simple liquid pre-wetting, is of essential value for the treatment of complicated real oil/water systems. Here, we first fabricated a stable suspension of imine-linked covalent organic framework nanospheres (TPB-DMTP-COF), and subsequently fabricated COF functionalized smart membranes with under-liquid dual superlyophobicity by immersing polyacrylonitrile-based (PAN-based) membranes into TPB-DMTP-COF nanosphere suspension. Accordingly, effective switchable separation of both oil-in-water and water-in-oil emulsions by TPB-DMTP-COF/PAN membranes can be achieved by employing pre-wetting processes (both the oil contact angle under water and the water contact angle under oil are over 150°). Specifically, the separation flux and the separation efficiency are higher than 1200 L/m2‧h and 98.0 %, and 2100 L/m2‧h and 97.4 % for the surfactant-stabilized oil-in-water and water-in-oil emulsions, respectively. Furthermore, the ultralow adhesions in liquid contributed to the outstanding reusability and antifouling resistance of the prepared TPB-DMTP-COF/PAN membranes. This work provides a feasible approach for fabricating a smart membrane with under-liquid dual superlyophobicity for oily wastewater treatment.

Isotopic and proteomic evidence for communal stability at Pre-Pottery Neolithic Jericho in the Southern Levant.

As one of the key, long-term occupied sites in the Southern Levant, Jericho was one of the most important early Neolithic centres to witness social and economic changes associated with the domestication of plants and animals. This study applies strontium (87Sr/86Sr), oxygen (δ18O) and carbon (δ13C) isotope analyses to the enamel of 52 human teeth from Pre-Pottery Neolithic (PPN) layers of Jericho to directly study human diet and mobility and investigate the degree of consolidation and the flexibility of social organization of Jericho society in the PPN period. The results indicate only two non-local individuals out of the 44 sampled inhabitants identified by strontium isotope analysis and are consistent with the presence of a largely sedentary community at PPN Jericho with no evidence for large-scale migration. We also construct strontium spatial baselines (87Sr/86Sr map) with local 87Sr/86Sr signatures for the sites across the Southern Levant based on systematic compilation and analysis of available data. In addition, we apply proteomic analysis of sex-specific amelogenin peptides in tooth enamel for sex estimation of the sampled individuals (n = 44), the results of which showed a sex-biased ratio (more male than female detected in this sample pool) in Jericho society during the PPN period, which may be due to the limited sample size or selective ritual practices like particular burial zones used for specific groups. We also pretreated a batch of human bone samples recovered from PPNB Jericho for stable carbon and nitrogen isotope analyses for dietary investigations. However, the extracted collagen showed poor preservation and no valid δ13C or δ15N data were obtained.

Fabrication and characterization of impact-resistant core-spun yarn fabrics with a hydroxylated fullerene-strengthened shear thickening fluid.

Shear thickening fluid (STF) is investigated to strength soft armor; however, its impact resistance still does not meet practical needs. In this work, a small amount of hydroxylated fullerene (C60) was mixed with STF to improve the thickening ratio. First, furfuryl alcohol (FA) was grafted onto C60 through a Diels-Alder (D-A) reaction to improve the dispersity of C60 in the STF. Sheath-core composite fibers (polyketone (PK) as the sheath and STF as the core) were then fabricated by coaxial electrospinning. Finally, composite fibers containing STF and C60 were wrapped on the surface of aramid yarns to fabricate a core-spun yarn. Under impact, these core-spun yarns manifested the characteristics of aramid fibers and the thickening advantages of the STF, solving problems of the hygroscopicity, migration, and leakage of STF. In addition, the content of STF was also greatly increased. The spike punching resistance of the core-spun yarn fabric is about 2.8 times that of the aramid fabric (AF) under the same area density. Impact-resistant core-spun yarn fabrics could provide a new direction for the development of soft armor.

Facial fabrication of few-layer functionalized graphene with sole functional group through Diels-Alder reaction by ball milling.

The widespread use of graphene as a next-generation material in various applications requires developing an environmentally friendly and efficient method for fabricating functionalized graphene. Chemically, graphene can be used as an electron donor or attractor. Here, graphite was successfully exfoliated, and an in situ Diels-Alder reaction (D-A) was carried out to fabricate functionalized graphene with sole functional groups via mechanochemical ball milling. The reactivities of graphene acting as a diene or a dienophile were investigated. Few-layer (≤2 layers) graphene specimens were obtained by wet ball milling, heating in a nitrogen atmosphere, and solvent ultrasonic treatment. The ball-milling method was more effective than heating in a nitrogen atmosphere, and the [2 + 4] D-A of graphene was more dominant than the [4 + 2] D-A in the ball-milling process. The surface tension of functionalized graphene decreased, which provided a theoretical basis for the dispersion and exfoliation of graphite in a suitable solvent. Functionalized graphene still had a high electrical conductivity, which has far-reaching significance for functionalized graphene to be applied in electronic semiconductors and related applications. Meanwhile, functionalized graphene was applied to polymer composite fibers, the tensile strength and the Young's modulus could reach 780 MPa and 19 GPa. The volume resistivity was two orders of magnitude lower than that of pure fiber. Thus, the use of ball milling to efficiently exfoliate and in situ functionalize graphite will help to develop a strategy that can be widely used to manufacture nanomaterials for various application fields.

Synthesis and characterization of microencapsulated phase change materials with chitosan-based polyurethane shell.

In this paper, chitosan-based polyurethane (c-PU) microencapsulated phase change materials (MicroPCMs) were prepared via the interfacial polymerization reaction of hexamethylene diisocyanate and chitosan accompanied by the charge attraction-assisted. The utilization of natural non-toxic chitosan in MicroPCMs expanded the application of chitosan and guided a new approach to preparing green shell. And the morphology of MicroPCMs with different reaction ration, surfactant and the pH value of reaction system were systematically investigated. The MicroPCMs with c-PU shell exhibited outstanding latent thermal performance (ΔHm = 106.3 J/g, ΔHc = -105.1 J/g), high energy storage efficiency (E = 71.4%), excellent thermal stability and cyclic durability. The c-PU MicroPCMs with reversible photochromic show promising application in the fields of anti-counterfeiting technology and flexible wearable UV protective clothing.

Molecular mechanism of mice gastric oxidative damage induced by nanoparticulate titanium dioxide.

BACKGROUND: Nanoparticulate titanium dioxide (Nano-TiO2) has been widely used in food industry, and it has been demonstrated to have adverse effects on mice and human stomach, but its mechanism is rarely concerned. The aim of this study is to determine the effects of nano-TiO2 on the stomach and confirm the role of oxidative stress and apoptosis in the mice gastric damage caused by nano-TiO2, as well as its molecular mechanisms. METHODS: Mice were continuously exposed to nano-TiO2 with 1.25, 2.5 and 5 mg/kg bw by intragastric administration for 9 months in the present study. The ultrastructure, levels of reactive oxygen species (ROS) and peroxides, activities of antioxidant enzymes and mitochondria-related enzymes, ATP contents as well as apoptosis-related factors expression in mice stomach were examined. RESULTS: Oxidative stress, apoptosis and nano-TiO2 aggregation were found in gastric mucosal smooth muscle cells after nano-TiO2 exposure. Nano-TiO2 exposure also resulted in the over-production of ROS and peroxides, decrease of ATP production and activities of antioxidant enzymes and mitochondria-related ATPases, upregulation of apoptosis-related factors including γH2AX, Cyt c, caspase 3, and p-JNK expression, and down-regulation of Bcl-2 expression in mice stomach. CONCLUSIONS: The gastric toxicity of mice induced by chronic exposure to low dose nano-TiO2 may be associated with oxidative stress and mitochondria-mediated apoptosis in mice.

Suppressing Thermal Negative Effect and Maintaining High-Temperature Steady Electrical Performance of Triboelectric Nanogenerators by Employing Phase Change Material.

Triboelectric nanogenerators (TENGs) are newly developed energy-harvesting mechanisms, which can efficiently transmute irregular mechanical energy into scarce electrical energy. However, the electrical performance of TENGs shows a decreasing tendency with the increase in temperature, and the negative effect caused by friction heat and operating environmental thermal stresses for the output performance, durability, and reliability are still a bottleneck, restricting the practical application of TENG electronic devices. Especially for wearable TENG devices, the heat-induced temperature rise evokes extreme discomfort and even hazards to human health. To effectively suppress the thermal negative effect and maintain the high-temperature steady electrical performance of TENGs, a novel thermo-regulating TENG (Tr-TENG) based on phase change materials (PCMs) is designed. The results state clearly that the Tr-TENG can maintain steady output performance without deterioration by the introduction of PCMs, during continuous heating and natural cooling, while the output performance of conventional TENG is decayed by 18.33%. More importantly, the Tr-TENG possesses high-efficiency thermal management ability, resulting in its improved durability, reliability, and thermal comfort. This study creates new possibilities for the development of advanced multifunctional TENGs with attractive characteristics and desirable performances and promotes the application of TENG electronic devices in harsh environments.