K-Means Based Constellation Optimization for Index Modulated Reconfigurable Intelligent Surfaces

Reconfigurable intelligent surface (RIS) has recently emerged as a promising technology enabling next-generation wireless networks. In this letter, we develop an improved index modulation (IM) scheme by utilizing RIS to convey information. Specifically, we study an RIS-aided multiple-input single-output (MISO) system, in which the information bits are conveyed by reflection patterns of RIS rather than the conventional amplitude-phase constellation. Furthermore, the K-means algorithm is employed to optimize the reflection constellation to improve the error performance. Also, we propose a generalized Gray coding method for mapping information bits to an appropriate reflection constellation and analytically evaluate the error performance of the proposed scheme by deriving a tight upper bound of the average bit error rate (BER). Finally, numerical results verify the accuracy of our theoretical analysis as well as the substantially improved BER performance of the proposed RIS-based IM transmission scheme.Comment: 5 pages, 3 figures, accepted by IEEE C

In situ grown palladium nanoparticles on polyester fabric as easy-separable and recyclable catalyst for Suzuki-Miyaura reaction

Palladium nanoparticles supported on low-melting polyester (Pd/LMPET) fabric were prepared through a microwave irradiation assisted method. In this way, in situ growth of Pd nanoparticles onto an easy to handle material was initiated and proceeded. The results of the characterization revealed that the palladium nanoparticles were well-dispersed on the surfaces of the polyester fibers. The Pd/LMPET fabrics were then employed in the Suzuki-Miyaura coupling. They exhibited excellent catalytic activity in ethanol/water under air atmosphere at 50 °C. Importantly, the Pd/LMPET fabrics could be separated from reaction mixture conveniently and they can still maintain good activity after 8 cycles without Pd leaching. © 2021 The Author

Morphological, anatomical and histological studies on knob and beak characters of six goose breeds from China

The knob serves as both a sexual indicator of a goose’s maturity and a significant packaging attribute that garners consumer attention. However, studies regarding the morphological, anatomical and histological traits of different breeds and ages on the on knob in goose are lacking. In this study, six breeds with typical goose knob types were selected, and their knob size, morphological, anatomical and histological traits were characterized. The results showed that: Knob was more prominent in gander than in female goose, and the difference was the most obvious in Magang goose. Wanxi white goose and Shitou goose had the largest knob bulge, while Magang goose and Sichuan white goose were smaller. The total knob volume of Wanxi White goose and Shitou goose was significantly higher than that of other breeds, regardless of male or female (p < 0.05). The beak volume of Wanxi White goose and gander was significantly higher than that of other goose breeds (p < 0.05). Furthermore, the observation revealed that the “knob” primarily consisted of skin-derived tissue and bony protrusions. As age advances, the knob of both male and female geese undergoes synchronous development, with the knob of male geese typically surpassing that of their female counterparts during the same period. The growth rate of knob in male goose was the fastest from 70 to 120 days of age, and slowed down from 300 to 500 days of age. The growth rate of knob in female goose was slower than that in male goose. There were essential differences in the composition of Yangzhou goose knob and Magang goose knob. The subcutaneous tissue of Magang goose was rich, and the thickness of epidermis, dermis and various layers was significantly smaller than that of Yangzhou goose (p < 0.05). With the growth of goose knob, the cells of the epidermal spinous layer became denser and gradually condensed into an overall structure, and there was a clear boundary between the dermis and epidermis after adult. In adulthood, the fiber fascicle network was staggered and dense, with greater toughness and elasticity, and the stratum corneum, epidermis, reticular layer, dermis and other skin structural layers became thicker

Gandouling alleviates nerve injury through PI3K/Akt/FoxO1 and Sirt1/FoxO1 signaling pathway to inhibit autophagy in the rats model of Wilson's disease

Abstract Introduction Previous studies have shown that Gandouling (GDL) may alleviate the nerve damage caused by Wilson's disease (WD) by inhibiting the autophagy of nerve cell mitochondria. However, its mechanisms are still unclear. Revealing the therapeutic mechanism of GDL is beneficial for its clinical application and provides theoretical support for the development of new formulations for treating WD. Method This time we found that the oxidative stress level in the body of the copper‐overloaded WD rates increased, neurons in the hippocampus were damaged, and autophagy occurred. GDL reversed these situations and significantly improved the learning, memory, and spatial cognitive abilities of the high‐copper‐loaded WD rates. After GDL intervention, the expression of phosphatidylinositol‐3 kinase (PI3K), phosphorylated serine–threonine protein kinase (AKT), and phosphorylated forkhead box protein O1 (FoxO1) significantly increased, whereas FoxO1 in the nucleus decreased and phosphorylated FoxO1 in the cytoplasm also significantly raised. In addition, the expression of Sirt1 significantly declined, and Ac‐FoxO1 in the nucleus also significantly increased. Results These data indicated that GDL may promote the phosphorylation of FoxO1 and promote its nucleation by activating the PI3K/AKT/FoxO1 signaling pathway and inhibit Ac‐FoxO1 hydrolysis in the nucleus through the Sirt1/FoxO1 signaling pathway to suppress the transcriptional activity of FoxO1. Conclusion Furthermore, it inhibited the expression of autophagy genes Atg12 and Gabarapl1. In summary, our work provides new insights into the potential mechanisms of GDL repairing WD neuronal damage through autophagy pathways

Sequencing and phylogenetic analysis of the complete chloroplast genome of Arisaema heterophyllum Blume

Arisaema heterophyllum Blume is a perennial medicinal herb widely distributed in China, Korea and Japan. In this study, the complete chloroplast genome sequence of A. heterophyllum was assembled and characterized based on high-throughput sequencing data. The whole chloroplast genome is 170,610 bp in length and contains 95,485 bp large single-copy (LSC) and 22,605 bp small single-copy (SSC) regions separated by a pair of 26,260 bp inverted repeat (IR) regions. It contained a total of 129 genes, including 84 protein-coding genes, 37 tRNA genes, and 8 rRNA genes, with an overall GC content of 34.5%. A phylogenetic tree reconstructed by 30 chloroplast genomes reveals that A. heterophyllum is mostly related to the same genus A. ringens, A. franchetianum and A. erubescens. The complete chloroplast genome of A. heterophyllum was the firstly reported and deposited at GenBank under accession number MZ424448

Distance controlled resonant radiation from modulated Airy pulses

We investigate the dynamic evolution of resonant radiation (RR) emitted from modulated Airy pulses in an optical fiber with emphasis on the third-order dispersion. We show that the process of RRs emission strongly depends on the parameters of the predesigned spectral phase imposed on the Airy pulses, which is attributed to its linear focusing behaviors. A localized pulse formed at the distance-controlled focusing can effectively generate a large amount of RR after a prescribed propagation distance. At variance with the case of fundamental soliton, the minimum value of third-order dispersion required for the onset of RRs emission becomes much smaller for the modulated Airy pulse. The conversion efficiency of RRs increases with an increasing linear focusing point, but decreases with an increasing truncated coefficient. There is an optimal value of the truncated coefficient for the RRs having highest peak intensity and largest frequency shift. The impact of Raman effects on the RRs is also revealed. Our results not only provide a simply route to actively manipulate the efficient emission of RRs in conventional optical fiber, also could have significant implications of pulse shaping technology in novel highly efficient light sources based on the RRs emission for a variety of application

Removal of As(V) from aqueous solution by using cement-porous hematite composite granules as adsorbent

The potential of using Portland cement-porous hematite composite granules (CHG) as a new adsorbent for the adsorption of As(V) from aqueous solution was investigated in this study. This research was performed through the measurements of adsorption isotherm, adsorption kinetics, X-ray diffraction (XRD), mercury intrusion porosimetry (MIP), scanning electron microscope (SEM) and energy dispersive X-ray detector (EDX). The pore structure of CHG was extraordinary developed with the porosity, the total pore volume and the average pore diameter being 45.48%, 0.3586 mL/g and 62.7 nm, respectively. From the adsorption batch of As(V) on porous hematite and CHG, CHG exhibited a high adsorption capacity of 9.84 mg/g for As(V), slightly lower than the porous hematite adsorbent. It was observed that CHG kept greater than 83% adsorption capacity of the porous hematite. However, CHG was convenient in solid-liquid separation after adsorption benefited from its high mechanical strength, stability in solutions and big size, which could be separated directly from the water without any other equipment and technology. As a result, this work provides a theoretical basis for the practical application of granular adsorbents to the actual As(V) sewage. Keywords: Porous hematite, Portland cement, Granule, As(V) adsorption, Solid-liquid separatio

Study on Comprehensive Technology of Preventing Mud Cake of Large Diameter Slurry Shield in Composite Stratum

When large-diameter slurry shields are tunneling in a composite stratum with a high clay content, the cutter head may form a mud cake. After the mud cake is formed, it will cover the cutter and reduce the opening rate of the cutter head, thus reducing the penetration of the cutter and the driving speed. Based on a road upgrading project, this paper studies the prevention and treatment of a mud cake and forms a set of comprehensive treatment methods. For a large mud cake, through theoretical analysis, two calculation methods of the cutter head sealing coefficient are obtained, and the cutter head sealing coefficient relationship model is established. Comparing the calculated cutter head’s actual opening coefficient with the required cutter head opening coefficient can provide a judgment basis for the time of manual warehousing. For medium and small mud cakes, the numerical simulation is carried out based on the cutter head and the scouring system, the distribution characteristics of the flow field near the cutter head are analyzed, and the angle of the central scouring hole is optimized. For a small mud cake, hydrogen peroxide is selected as an additive through microscopic mechanism analysis. The effect of the hydrogen peroxide solution concentration on dissolving a mud cake is obtained through laboratory tests, and its effectiveness is verified through field tests. The research results can provide a reference for the mud cake prevention of slurry shields in similar strata