A Facile Fabrication of Silver-Coated Copper Nanowires by Galvanic Replacement

We demonstrated a general strategy to fabricate silver-coated copper nanowires by a galvanic replacement, which is guided by the chemical principle that metal ions (silver ions) with a relatively high reduction potential can galvanically etch nanostructure made from a less metal (copper). Well-dispersed and high-yielded copper nanowires were initially synthesized and then introduced into silver-ammonia solution for the growth of silver nanocrystals on the nanowire surfaces under vigorous oscillation. The results of X-ray diffraction, scanning electron microscope, and transmission electron microscope revealed that the silver nanocrystals were uniformly distributed on the copper nanowire surfaces to form Cu-Ag heterostructures. The concentration of silver-ammonia solution and the time of replacement reaction determine the size and density of the silver nanocrystals. Our investigation might pave the way to the synthesis of other bimetallic nanostructures via a facile, fast, and economical route

The Mediating Role of Social Capital in Digital Information Technology Poverty Reduction an Empirical Study in Urban and Rural China

Widespread use of digital information technology is having a significant impact on economic growth and people’s well-being. This paper assesses the mediating role of social capital in the impact of digital information technology on multidimensional poverty. Due to differences in regional, industrial structure and other factors, digital information technology has different impacts on urban and rural residents. In this paper, the China Family Panel Studies (CFPS) database is used for data, and a mediating effect model is used to study the problem. The digital information technology use was found to enhance social capital from social network, social participation and social trust, and subsequently alleviates multidimensional poverty. The results indicate that social trust plays a more significant mediating role than social capital and social participation on the impact of digital information technology on multidimensional poverty. Furthermore, the results reveal that the use of digital information technology has varying effects on poverty reduction among different income groups, with a much higher effect on low-income groups. However, the mediating effect of social capital in high-income groups is higher than that in low-income groups. In particular, social capital in the top 25% of income groups has the highest mediating effect. In the heterogeneity analysis between urban and rural areas, it is found that the multidimensional poverty situation in urban areas is significantly better than that in rural areas, because urban residents have a higher use of digital information, and at the same time, the quality of social capital in urban and rural groups is different, leading to the difference in the effect of digital information technology on poverty reduction of multidimensional poverty. Based on the results of the study, we believe that the use of digital information technology has actually improved the multi-dimensional poverty status of all groups, and social capital plays a key mediating role in it. Relying on the progress of digital information technology, we can build more convenient social network. Establish more adequate channels of information communication, enhance social trust and social participation, and alleviate multidimensional poverty

2D Meso/Microporous Platelet Carbon Derived from Metal-Organic frameworks and Its Application in High-Performance Li-S Batteries

A cathode consisting of 2D homogeneous micro/mesoporous platelet carbon (MMPC) is synthesized in one step by regulated pyrolysis of metal-organic frameworks (MOF), which act as self-templates. The uniform micro/mesoporous structure is ascribed to metal sublimation in the Zn-based MOF during the pyrolysis process. The cathode exhibits an excellent cycling performance due to the homogeneous distribution of micro/mesopores and the 2D nanosheet structure, which does not only lead to the loading of evenly distributed, ultrafine sulfur, but also favors the depressing shuttle effect and a rapid electron transfer. Meanwhile, reduced oxide graphene (rGO) - as the conductive agent - is beneficial for the continuity of the electron-transport path and for increasing the utilization of active materials. The optimized MMPC cathode exhibits a superior cycling stability at a rate of 1 C, with 1500 cycles, and an outstanding rate-cycle performance with an initial discharge capacity of 670.1 mAh g(-1) and a good cycling stability after 400 cycles at a rate of 5 C

UAV-Assisted Three-Dimensional Spectrum Mapping Driven by Spectrum Data and Channel Model

As the number of civil aerial vehicles increase explosively, spectrum scarcity and security become an increasingly challenge in both the airspace and terrestrial space. To address this difficulty, this paper presents an unmanned aerial vehicle-assisted (UAV-assisted) spectrum mapping system and a spectrum data reconstruction algorithm driven by spectrum data and channel model are proposed. The reconstruction algorithm, which includes a model-driven spectrum data inference method and a spectrum data completion method with uniformity decision mechanism, can reconstruct limited and incomplete spectrum data to a three-dimensional (3D) spectrum map. As a result, spectrum scarcity and security can be achieved. Spectrum mapping is a symmetry-based digital twin technology. By employing an uniformity decision mechanism, the proposed completion method can effectively interpolate spatial data even when the collected data are unevenly distributed. The effectiveness of the proposed mapping scheme is evaluated by comparing its results with the ray-tracing simulated data of the campus scenario. Simulation results show that the proposed reconstruction algorithm outperforms the classical inverse distance weighted (IDW) interpolation method and the tensor completion method by about 12.5% and 92.3%, respectively, in terms of reconstruction accuracy when the collected spectrum data are regularly missing, unevenly distributed and limited

Screen-Printed Fabrication of PEDOT:PSS/Silver Nanowire Composite Films for Transparent Heaters

A transparent and flexible film heater was fabricated; based on a hybrid structure of poly(3,4-ethylenedioxythiophene) poly(styrenesulfonate) (PEDOT:PSS) and silver nanowires (Ag NWs) using a screen printing; which is a scalable production technology. The resulting film integrates the advantages of the two conductive materials; easy film-forming and strong adhesion to the substrate of the polymer PEDOT:PSS; and high conductivity of the Ag NWs. The fabricated composite films with different NW densities exhibited the transmittance within the range from 82.3% to 74.1% at 550 nm. By applying 40 V potential on the films; a stable temperature from 49 °C to 99 °C was generated within 30 s to 50 s. However; the surface temperature of the pristine PEDOT:PSS film did not increase compared to the room temperature. The composite film with the transmittance of 74.1% could be heated to the temperatures from 41 °C to 99 °C at the driven voltages from 15 V to 40 V; indicating that the film heater exhibited uniform heating and rapid thermal response. Therefore; the PEDOT:PSS/Ag NW composite film is a promising candidate for the application of the transparent and large-scale film heaters

Image_1_Plasma single-stranded DNA autoantibodies in the diagnosis of Hirschsprung’s disease.JPEG

BackgroundHirschsprung’s disease (HSCR) is a neonatal enteric nervous system (ENS) disease characterized by congenital enteric ganglion cell loss. The only treatment is aganglionic bowel segment resection and innervated bowel segment reconstruction. Delayed diagnosis and treatment cause postoperative complications such as intractable constipation and enterocolitis. Existing preoperative HSCR diagnostic methods have shortcomings such as false positives, radiation and invasiveness.MethodsWe used the robust linear model (RLM) for normalization and the M statistic for screening plasma human autoimmune antigen microarrays and quantitatively assessed single-stranded DNA (ssDNA) antibody levels with enzyme-linked immunosorbent assay (ELISA).ResultsThe autoimmune antigen microarray revealed that autoantibodies were higher in HSCR plasma than in disease control (DC) and healthy control (HC) plasma. ssDNA antibodies in HSCR plasma were significantly higher than those in DC and HC plasma. Quantitative ssDNA antibody level detection in plasma by ELISA showed that HSCR (n = 32) was 1.3- and 1.7-fold higher than DC (n = 14) and HC (n = 25), respectively. ssDNA antibodies distinguished HSCR from non-HSCR (HC and DC), achieving an area under the curve (AUC) of 0.917 (95% CI, 0.8550–0.9784), with a sensitivity of 96.99% and a specificity of 74.63%.ConclusionssDNA antibodies in plasma can serve as a diagnostic biomarker for HSCR in the clinic.</p