Origami metamaterials for ultra-wideband and large-depth reflection modulation.

The dynamic control of electromagnetic waves is a persistent pursuit in modern industrial development. The state-of-the-art dynamic devices suffer from limitations such as narrow bandwidth, limited modulation range, and expensive features. To address these issues, we fuse origami techniques with metamaterial design to achieve ultra-wideband and large-depth reflection modulation. Through a folding process, our proposed metamaterial achieves over 10-dB modulation depth over 4.96 - 38.8 GHz, with a fractional bandwidth of 155% and tolerance to incident angles and polarizations. Its ultra-wideband and large-depth reflection modulation performance is verified through experiments and analyzed through multipole decomposition theory. To enhance its practical applicability, transparent conductive films are introduced to the metamaterial, achieving high optical transparency (>87%) from visible to near-infrared light while maintaining cost-effectiveness. Benefiting from lightweight, foldability, and low-cost properties, our design shows promise for extensive satellite communication and optical window mobile communication management.

Optimizing Electron Spin-Polarized States of MoSe2 /Cr2 Se3 Heterojunction-Embedded Carbon Nanospheres for Superior Sodium/Potassium-Ion Battery Performances.

The principal challenges faced by sodium-ion batteries (SIBs) and potassium-ion batteries (KIBs) revolve around identifying suitable host materials capable of accommodating metal ions with larger dimensions and addressing the issue of sluggish chemical kinetics. Herein, a MoSe2 /Cr2 Se3 heterojunction uniformly embedded is fabricated in nitrogen-doped hollow carbon nanospheres (MoSe2 /Cr2 Se3 @N-HCSs) as an electrode material for SIBs and KIBs. Cr2 Se3 exhibits spontaneous antiparallel alignment of magnetic moments. Mo2+ doping is employed to regulate the electron spin states of Cr2 Se3 . Moreover, the MoSe2 and Cr2 Se3 heterojunctions induce a lattice mismatch at the heterostructure interface, resulting in spin-polarized states or localized magnetic moments at the interface, potentially contributing to spin-polarized surface capacitance. MoSe2 /Cr2 Se3 @N-HCSs demonstrate a high capacity of 498 mAh g-1 at 0.1 A g-1 with good cycling stability (capacity of 405 mAh g-1 and a coulombic efficiency of 99.8% after 1000 cycles). Additionally, density functional theory (DFT) calculations simulate the accumulation of spin-polarized charges at the MoSe2 /Cr2 Se3 @N-HCSs heterojunction interface, dependent on the surface electron density of the antiferromagnetic Cr2 Se3 and the surface spin polarization near the Fermi level. After regulating the electron spin states through Mo-doping, the band gap of the material decreases. These significant findings provide novel insights into the design and synthesis of electrode materials with exceptional performance characteristics for batteries.

Yolk-Shell MnSe/ZnSe Heterostructures with Selenium Vacancies Encapsulated in Carbontubes for High-Efficiency Sodium/Potassium Storage.

The pursuit of high-performance batteries has propelled the investigation into advanced materials and design methodologies. Herein, the yolk-shell MnSe/ZnSe heterojunction encapsulated in hollow carbontubes (MnSe/ZnSe@HCTs) is prepared as a prospective electrode material for sodium/potassium batteries. The band structure in the heterojunction is methodically adjusted and regulated by intentionally utilizing Mn with unpaired electrons in the 3d orbital. The ZnSe shell confer effectively mitigates volumetric expansion challenges inherent in ions insertion/extraction processes and 1D carbontubular conductive substrate avert the aggregation of MnSe/ZnSe nanoparticles. Concurrently, the heterojunctions implantation induces sublattice distortion and charge redistribution, enriching active sites and regulating band structure. The selenium vacancies within these heterojunctions contribute to the provision of abundant active sites, thereby promoting efficient ions insertion/extraction. In sodium-ion batteries (SIBs), MnSe/ZnSe@HCTs present a superior capacity of 475 mA hg-1 at 0.1 A g-1 and sustains a capacity of 408.5 mAh g-1 even after 1000 cycles. In potassium-ion batteries (KIBs), MnSe/ZnSe@HCTs deliver a higher specific capacity of 422 mAh g-1 at a current density of 0.1 A g-1 and maintain a high coulombic efficiency of 99% after 1000 cycles. The yolk-shell structured MnSe/ZnSe heterojunction demonstrates excellent electrode properties for high-performance sodium/potassium batteries, holding significant promise for future energy storage applications.

Altitude measurement method of VHF radar based on spatial smoothing of correlation matrix.

For very high frequency (VHF) phased array radar, the key problem to be solved in altitude measurement is the super-resolution spatial spectrum estimation under the condition of coherent sources. The spatial smoothing algorithm is a kind of decorrelation algorithm with excellent properties, but the decorrelation process is at the expense of the effective array aperture. Because it only uses the autocorrelation information of the subspace, its performance is significantly reduced, when the positions of the coherent sources are very close. In order to solve the above problems, this paper proposes an altitude measurement method of VHF radar based on the space smoothing of autocorrelation and cross-correlation matrix, which is used to realize the correlation and super-resolution processing of echo signals and multipath signals. The proposed method does not need to construct a weighting matrix, and can make full use of the received data, enhance the signal components in the equivalent spatial smoothing matrix, reduce the impact of noise, and improve the resolution of coherent sources. The simulation results show that the weighted spatial smoothing method proposed in this paper is correct and effective.

Effects of different allo-Treg/allo-NK ratios on graft-versus-host disease in transplanted mice.

To investigate the effects of allo-Treg cells, allo-NK cells, and their mixtures in different proportions on Graft-versus-host disease (GVHD) in bone marrow transplant mouse model. In this study, C57BL/6 mice were used as donors, and 6 Gy dose of 60Co γ was used as the receptor of BALB/c mice. The recipient mice were divided into NC (normal saline), CON (bone marrow cells), NK (bone marrow cells + NK cells), Treg (bone marrow cells + Treg cells), NK+ Treg (1:1) (bone marrow cells +1:1 ratio of Treg cells, NK cells), and NK+ Treg (6:1) (bone marrow cells +1:6 ratio of Treg cells, NK cells), according to the different injection mode through the tail vein. The differences of white blood cell (WBC), platelet (PLT), clinical manifestations, and GVHD score of target organs (liver, lung, small intestine) in each group after transplantation were observed, and the differences of chimerism rate and survival rate in each group at 28 days after transplantation were compared. The interaction between Treg cells and NK cells in different proportions (1:1, 1:2, 1:6, 1:12) was investigated in vitro in mouse erythroleukemia (MEL) cells of mouse erythroleukemia. The results showed that at the 28th day of transplantation, the clinical manifestations and GVHD scores of target organs of mice in NK+ Treg (1:1) group and NK+ Treg (6:1) group were significantly lower than other groups (P < 0.05); the WBC and PLT counts were significantly higher than other groups (P < 0.05), and the survival time was significantly longer than other groups (P < 0.05); the clinical manifestations and GVHD scores of each target organ in NK+ Treg (1:1) group were significantly lower than those in NK+ Treg (6:1) group (P < 0.05); the chimerism rate of each group was >90% on day 28 after transplantation. In vitro experiments showed that the inhibition of Treg cells on NK cell killing activity was dose-dependent, and the proportion of 1:6 and 1:12, killing activity of NK cell was significantly lower than that of groups 1:1 and 1:2 (P < 0.05), which showed that allo-NK and allo-Treg alone had a significant effect on the improvement of GVHD after transplantation, and Treg cells inhibited the killing activity of NK cells by direct contact and showed a dose-dependent effect.

Molybdenum sulfide selenide ultrathin nanosheets anchored on carbon tubes for rapid-charging sodium/potassium-ion batteries.

The structural stability and reaction kinetics of anodes are essential factors for high-performance battery systems. Herein, the molybdenum sulfide selenide (MoSSe) nanosheets anchored on carbon tubes (MoSSe@CTs) are synthesized by a facile hydrothermal method combining with further selenization/calcination treatment. The unique tubular carbon skeletons expose abundant active sites for the well-dispersed growth of MoS2 ultrathin nanosheets on both sides of the tubular carbon skeleton. In addition, the further selenization treatment can expand the interlayer spacing of molybdenum sulfide (MoS2) nanosheets and facilitate the fast sodium/potassium-ion transition and storage. When used in sodium-ion batteries (SIBs), MoSSe@CTs electrode delivers a specific capacity of 486 mAh g-1 at 1 A g-1 and retains a stable reversible capacity of 465 mAh g-1 after 1000 cycles, indicating its good cycling stability. For potassium-ion batteries (KIBs), the MoSSe@CTs composite shows a capacity of 352 mA hg-1 at 1 A g-1 and a good cycling stability (maintains at 272 mA hg-1 after 1000 cycles). This work shows informative guiding significance for exploring advanced electrode materials of sodium/potassium-ion batteries.

Assessment of heavy metal contamination in surface sediments in the western Taiwan Strait.

The concentrations of the heavy metals Cu, Pb, Zn, As, Cr, Co, and Ni of a total of 187 surface sediment samples collected from the western Taiwan Strait were analyzed. The distribution characteristics and degree of contamination of these elements were investigated. The mean concentrations of Cu, Pb, Zn, As, Cr, Co, and Ni in the surface sediments of the study area were 10.2 mg/kg, 18.3 mg/kg, 51.7 mg/kg, 7.5 mg/kg, 38.7 mg/kg, 8.0 mg/kg, and 16.5 mg/kg, respectively. The heavy metals in the study area were mainly from natural sources. The regional pollution load index (PLIzone) was 0.64, indicating that there was no contamination, and an area with a relatively high PLIzone was found in the northern part of the study area. Furthermore, the impacts of the rapid development of Fujian's marine economy on the marine environment in the past decade should be further compared and analyzed.

Urchin-like Amorphous Nitrogen-Doped Carbon Nanotubes Encapsulated with Transition-Metal-Alloy@Graphene Core@Shell Nanoparticles for Microwave Energy Attenuation.

Herein, we report three-dimensional (3D) urchin-like amorphous nitrogen-doped CNT (NCNT) arrays with embedded cobalt-nickel@graphene core@shell nanoparticles (NPs) in the inner parts of NCNTs (CoNi@G@NCNTs) for highly efficient absorption toward microwave (MW). The CoNi NPs are covered with about seven layers of graphene shell, resulting in the formation of CoNi@G core-shell structures. In the meanwhile, the CoNi@G core-shell NPs are further encapsulated within NCNTs. Benefitting from the multiple scattering of the unique 3D structure toward MW, cooperative effect between magnetic loss and dielectric loss, and additional interfacial polarizations, the 3D urchin-like CoNi@G@NCNTs exhibit excellent MW energy attenuation ability with a broad absorption bandwidth of 5.2 GHz with a matching thickness of merely 1.7 mm, outperforming most reported absorbers. Furthermore, the chemical stability of the 3D urchin-like CoNi@G@NCNTs is improved greatly due to the presence of the graphene coating layers and outmost NCNTs, facilitating their practical applications. Our results highlight a novel strategy for fabrication of 3D nanostructures as high-performance MW-absorbing materials.

Design and implementation of the modified signed digit multiplication routine on a ternary optical computer.

Multiplication with traditional electronic computers is faced with a low calculating accuracy and a long computation time delay. To overcome these problems, the modified signed digit (MSD) multiplication routine is established based on the MSD system and the carry-free adder. Also, its parallel algorithm and optimization techniques are studied in detail. With the help of a ternary optical computer's characteristics, the structured data processor is designed especially for the multiplication routine. Several ternary optical operators are constructed to perform M transformations and summations in parallel, which has accelerated the iterative process of multiplication. In particular, the routine allocates data bits of the ternary optical processor based on digits of multiplication input, so the accuracy of the calculation results can always satisfy the users. Finally, the routine is verified by simulation experiments, and the results are in full compliance with the expectations. Compared with an electronic computer, the MSD multiplication routine is not only good at dealing with large-value data and high-precision arithmetic, but also maintains lower power consumption and fewer calculating delays.

Interior reconstruction method based on rotation-translation scanning model.

In various applications of computed tomography (CT), it is common that the reconstructed object is over the field of view (FOV) or we may intend to sue a FOV which only covers the region of interest (ROI) for the sake of reducing radiation dose. These kinds of imaging situations often lead to interior reconstruction problems which are difficult cases in the reconstruction field of CT, due to the truncated projection data at every view angle. In this paper, an interior reconstruction method is developed based on a rotation-translation (RT) scanning model. The method is implemented by first scanning the reconstructed region, and then scanning a small region outside the support of the reconstructed object after translating the rotation centre. The differentiated backprojection (DBP) images of the reconstruction region and the small region outside the object can be respectively obtained from the two-time scanning data without data rebinning process. At last, the projection onto convex sets (POCS) algorithm is applied to reconstruct the interior region. Numerical simulations are conducted to validate the proposed reconstruction method.

Fast reconstruction of flat region in a super-short scan based on MD-FBP algorithm.

In circular cone-beam computed tomography (CT), although the minimum data filtered-backprojection (MD-FBP) algorithm has many significant applications, such as handling super-short scan problem, its reconstruction efficiency is limited by the heavy calculation of backprojection. In this paper, aiming at the image reconstruction of flat region in a super-short scan, an improved method based on MD-FBP algorithm is developed using an integral operation with fixed integral interval during the implementation of backprojection, which has an improvement in reconstruction efficiency and parallel performance compared with the original MD-FBP algorithm. It is found that if the thickness of the flat region is less than 0.0349 R (R is the scanning radius), the uncertainty of the method can be ignored. When the thickness of reconstructed region is a little fat, it can also be reconstructed by increasing the scanning radius befittingly. The results of numerical simulation and real data experiments have demonstrated the correctness and merits of the proposed method.

Control method for the optical components of a dynamically reconfigurable optical platform.

We propose a control method for the optical components of a dynamically reconfigurable optical platform, the ternary optical computer (TOC). The optical components are made of liquid-crystal cell arrays (LCCAs) and polarizers, so the control method is for generating the pilot signals of the LCCAs to meet user demands. In this work, we first briefly introduce the TOC theory, the modules in the TOC monitor system, and the addressing of these LCCAs. Then we focus on the method for generating the control information (CI) of optical components, i.e., the encoder and the operator in the TOC according to the operands and the information about the basic operating units needed by an operation. In addition, we define data structures, some of which store the information to generate the CI and others that mainly store the generated CI. Finally we provide an example to verify the proposed method and conduct an experiment to generate the LCCA CI. The results demonstrate the correctness and feasibility of the method.

Carry-free vector-matrix multiplication on a dynamically reconfigurable optical platform.

Applying the parallelism of optical computing, we present a novel method of vector-matrix multiplication (VMM) based on a new optical computing platform, the ternary optical computer, which can reconfigure any two-input trivalued logic optical processor at runtime, according to the decrease-radix design principle. In this work, we investigate a novel optical VMM (OVMM) using five logic operations with the modified signed-digit (MSD) number system. To simplify the computation process, we realize a carry-free optical addition in three steps, which is independent of the length of the operands. And a new implementation method is proposed that can be used to realize the MSD multiplication in parallel. Based on the generation of partial products in parallel and the binary-addition-tree algorithm, the multiplication can be implemented with the MSD addition. Our initial experiments have been performed to verify the proposed OVMM method. The results show that the proposed method of OVMM is feasible and correct.