Perfect match between borophene and aluminium in AlB3 heterostructure with covalent Al-B bonds, multiple Dirac points and high fermi velocity

By performing swarm-intelligent global structure search combined with first-principles calculations, a stable two-dimensional (2D) AlB3 heterostructure with directed, covalent Al-B bond forms due to a nearly perfect lattice match between...

Zapach wojny i gór. Huculi i Huculszczyzna w międzywojennej literaturze polskiej o tematyce współczesnej (część II)

The article is the second part of a comprehensive study on representations of Hutsuls and the Hutsul region in the interwar Polish literature, which showed them during the First World War and the wars for the borders of the Second Polish Republic, as well as in the 1920s and 1930s. The article discuses, first and foremost, literary visions of Hutsuls and their native land in the third and fourth decade of the 20th century. The interwar Polish literature, which showed the Hutsul region “of today”, paid special attention to peacetime partnership of Poles and Hutsuls, which was to follow their wartime joint actions against Russians in the Eastern Carpathians in 1914–1915. It implied that this partnership was a result of a perfect match between the Polish national component and the Hutsul ethnic element. The article argues that Polish literature showed the compatibility of Poles and Hutsuls in the macro and micro dimensions. On the macro level, it was to be manifested, on the one hand, in the effective help of the Polish state institutions for Hutsuls, on the other hand, in the gratitude of Hutsuls for Poles. On the micro level, the Polish-Hutsul compatibility was to be manifested in friendly or intimate relations of representatives of both groups; relations which were invariably successful in spite of the fact that the Polish side dominated them and felt entitled to lead a civilization mission among Hutsuls. Such literary visions presented the Hutsul region as an integral part of the Second Polish Republic and its indigenous inhabitants as loyal citizens of the entire country. They also made it clear that Hutsuls affirmed Polishness and that Poles were welcomed and needed in the Hutsuls’s land.

The Perfect Match: Adjusting High Tree Density to Rootstock Vigor for Improving Cropping and Land Use Efficiency of Sweet Orange

The rise in the productivity of sweet orange in Brazil has been related to the use of superior rootstocks and higher tree density, among other factors. In order to investigate whether the cropping system and the land use efficiency would benefit from more intensive cultivation, the performance of Valencia sweet orange was evaluated over nine years on four rootstocks, which induced contrasting vigor, at 513, 696 and 1000 trees·ha−1. Agronomic Institute of Campinas (IAC) 1697 and IAC 1710 citrandarins, and diploid and allotetraploid (4×) Swingle citrumelos were classified as semi-dwarfing, super-standard, standard, and dwarfing rootstocks, respectively. The fruit yield per tree was decreased at higher tree densities, notably for more vigorous rootstocks. Conversely, the cumulative productivity was increased over the evaluation period by 27% at 1000 trees·ha−1, irrespective of the rootstock, and the most vigorous rootstock resulted in 2.5 times higher production than the dwarfing one on average. Most fruit quality parameters were seldom influenced by the tree density, while the rootstock was a decisive factor in improving the quality and the soluble solids content. Dwarfing rootstocks allowed for harvesting 17% more fruit per minute by manual pickers. Because the tree row volume per area is lower with such rootstocks, even at higher tree density, spray volume can be reduced, although appropriate equipment should be developed for better spray coverage on smaller trees. Nine years after planting under strict vector control, the cumulative incidence of huanglongbing-symptomatic trees on IAC 1710 was double that on Swingle 4×. Taken together, the results suggested that the land use efficiency in the citrus industry can be further improved by planting vigorous rootstocks at moderate to high tree densities. Nevertheless, obtaining highly productive semi-dwarfing and dwarfing rootstocks is the sine qua non for making high-density pedestrian sweet orange orchards more profitable.

Maternal parity affects Day 8 embryo gene expression in old mares

As sport career is a priority in most of equine breeds, mares are frequently bred for the first time at an advanced age. Both age and first gestation were shown to have a deleterious effect on reproduction outcomes, respectively on fertility and offspring weight but the effect mare's parity in older mares on embryo quality has never been considered. The aim of this project was to determine the effect of old mare's nulliparity on gene expression in embryos. Day 8 post ovulation embryos were collected from old (10-16 years old) nulliparous (ON, N=5) or multiparous (OM, N=6) non-nursing Saddlebred mares, inseminated with the semen of one stallion. Pure (TE_part) or inner cell mass enriched (ICMandTE) trophoblast were obtained by embryo bisection and paired end, non-oriented RNA sequencing (Illumina, NextSeq500) was performed on each hemi-embryo. To discriminate gene expression in the ICM from that in the TE, deconvolution (DeMixT R package) was used on the ICMandTE dataset. Differential expression was analyzed (DESeq2) with embryo sex and diameter as cofactors using a false discovery rate <0.05 cutoff. Although the expression of only a few genes was altered by mare's nulliparity (33 in ICM and 23 in TE), those genes were related to nutrient exchanges and responses to environment signaling, both in ICM and TE, suggesting that the developing environment from these mares are not optimal for embryo growth. In conclusion, being nulliparous and old does not seem to be the perfect match for embryonic development in mares.

Multilayer thin-film based nanophotonic windows: static versus electrotunable design

To meet the global energy demand, rapid growth in fossil fuel consumption has significantly contributed to global warming. Judicious utilization of renewable energy resources could help to combat this global challenge. Here, we present a comparative study on the designs of static and electro-tunable ‘smart’ windows that could help to reduce the energy need of typical airconditioning systems deployed in buildings and motor vehicles. Our design comprises insulator–metal–insulator multi-layered thin-films deposited over a silica glass substrate to filter visible and infrared solar radiation selectively. For static windows, we optimize our design to operate in diverse climatic conditions by choosing different combinations and thicknesses of metal and insulator layers. Whereas for electro-tunable windows, we use an electro–optic polymer as the insulator layers to dynamically control portions of transmitted solar radiation over a voltage range of −12 V to +12 V. Through size-dependence analysis, we could safely assume that the performance of smart windows is less likely to degrade during experimental realization. Our designs are lithography-free, large-area compatible, polarization-independent, angle-insensitive, and robust to fabrication imperfections. The analytical results show a near-perfect match with the simulation findings. The theoretically calculated figure of merit indicates that our proposed smart windows can outperform industry-standard commercial windows.

Design of Thin and Wideband Microwave Absorbers Using General Closed-Form Solutions

A new design method for RLC reactive absorbers is presented. This method is based on closed-form solutions to help realize the widest absorption bandwidth for an arbitrarily specified thickness. The solutions for the RLC values of the reactive screen are derived using an equivalent circuit in which the thickness of the substrate used, the permittivity and tangential loss of the substrate, and the frequency are all considered. A perfect match and maximum bandwidth at a design frequency can be achieved with the proposed method. Various aspects of the absorber characteristics, depending on the thickness and loss of the substrate, are analyzed using the presented solutions and electromagnetic (EM) simulations. To validate the proposed design method, an X-band microwave absorber with a crossed-dipole structure patterned on a silver nanowire resistive film is designed, fabricated, and measured. The substrate electrical thickness of the absorber is 70° at 10 GHz, with a permittivity of 2.2. The 90% absorption bandwidth is 8 GHz in the frequency range of 8.2–16.2 GHz. The measured absorption agrees well with the results obtained using circuit and EM simulations.

Confining the Inner Space of Strained Carbon Nanorings

Strained aromatic macrocycles based on cycloparaphenylenes (CPPs) are the shortest repeating units of armchair single-walled carbon nanotubes. Since the development of several new synthetic methodologies for accessing these structures, their properties have been extensively studied. Besides the fundamental interest in these novel molecular scaffolds, their application in the field of materials science is an ongoing topic of research. Most of the reported CPP-type macrocycles display strong binding toward fullerenes, due to the perfect match between the convex and concave π-surfaces of fullerenes and CPPs, respectively. Highly functionalized CPP derivatives capable of supramolecular binding with other molecules are rarely reported. The synthesis of highly functionalized [n]cyclo-2,7-pyrenylenes leads to CPP-type macrocycles with a defined cavity capable of binding non-fullerene guests with high association constants.

Revisiting the carbon mesopore contribution towards improved performance of ionic liquid–based EDLCs at sub-zero temperatures

The important role of mesopores has been investigated in electric double-layer capacitors (EDLCs) operating from 24 °C down to − 40 °C by using two in-house synthesized carbons with hierarchical porosity. These carbons were prepared from colloidal nanoparticles of SiO2 as the template and d-glucose as the carbon source. A decrease in the average diameter of the nanoparticles from 12 to 8 nm results in increased surface area and offers a perfect match between ions of binary mixture of imidazolium-based fluorinated ionic liquids and the pores of carbon. Short-range graphene layers produced with 8-nm silica nanoparticles lead to the creation of transport channels which better accommodate ions. We explain these findings per coulombic interactions among the ions and between the pore wall and the ionic species under confinement and electrochemical polarization conditions. Further, it is shown that a microporous carbon (another in-house produced rice-husk carbon SBET = 1800 m2∙g−1) performs better than hierarchical carbons at room temperature; however, thanks to the large fraction of mesopores, the latter exhibit far higher capacitance down to − 40 °C. While the ordering of ions in confinement is more critical at room temperature and dictated by the micropores, low temperature performance of supercapacitors is determined by the mesopores that provide channels for facile ion movement and keep the bulk ionic liquid–like properties. Graphical abstract

Physics in architecture projects, a perfect match on Alamillo’s bridge by Santiago Calatrava

The Alamillo’s bridge by Santiago Calatrava was studied, who develops projects and structures with morphological, sculptural, and conceptual aspects associated with physics and contemporary architecture, through experimentation with forms of nature, the movement of the human body and, materials such as steel and reinforced concrete. The methodological framework corresponded to a documentary study that determined the importance of the bridge from its historical context as part of the infrastructure of the 1992 Universal Exposition in Seville, as well as the analysis of the physical concepts used in its design and construction; and, a quantitative-descriptive study applied to the seventh semester students of the Architecture program of the Universidad Francisco de Paula Santander, Colombia, which determined their level of recognition of the physical concepts of this project. As a finding, it is highlighted that this bridge applied physical concepts such as: aerodynamics, torsion, compression, tension, traction, and gravitation, in compliance with its formal-aesthetic design criteria, and those students recognize the physical concepts, design and technical characteristics-formal, typical of the project. Likewise, it was determined that this urban landmark represents a comprehensive solution that solves the structure and form through solutions associated with the field of engineering, architecture, and physics.