Search

The germanium (Ge) anode attains wide attention in lithium‐ion batteries because of its high theoretical volumetric capacity (8646 mAh cm−3). However, the huge volume expansion (≈230%) results in its poor electrochemical performances. The strategies reported in the literature to solve the issue often cause a low packing density, lowering the volumetric capacity. Here, a pressure‐induced route is proposed to fabricate a Ge architecture, in which nano‐sized Ge (≈15 nm) is encapsulated by robust TiO2 and highly conductive carbon, which offer the advantages of a low stress–strain characteristic, low volume expansion in thickness change, high electrical conductivity (463.2 S m−1), high Li‐ion diffusion coefficient (9.55 × 10−9–8.51 × 10−12 cm2 s−1), and high tapping density (1.79 g cm−3). As a result, the dense architecture obtains outstanding volumetric capacities of 3559.8 mAh cm−3 at 0.1 A g−1 and 2628.2 mAh cm−3 at 20 A g−1, along with excellent cycling life over 5000 cycles at 10 A g−1. Remarkably, the full cell achieves a high volumetric energy density of 1760.1 Wh L−1, along with impressive fast‐charging performances and long cycling life. This work provides a new synthesis strategy and deep insight into the design of high‐volumetric capacity alloy‐based lithium‐ion‐battery anodes. [ABSTRACT FROM AUTHOR]

Iron sulfide (FeS) has been extensively studied as sodium‐ion battery anodes due to its high theoretical capacity (609 mAh g−1), but its large volume expansion and low electrical conductivity result in unsatisfactory cycling life and poor rate performance. Moreover, the sodium ion storage mechanism of FeS at a voltage range of 0.01–1 V involving conversion reactions and subsequent ion storage process is unclear yet. Here, the study proposes a vapor‐pressure induced synthesis route to fabricate FeS/C yolk‐shell structure that ultrathin carbon layers coat on the surface of FeS nanosheets, which can accommodate volume expansion of FeS during sodiation observed via in situ transmission electron microscope and improve its electrical conductivity. Remarkably, an in situ magnetometry reveals that vast spin‐polarized electrons can be injected into superparamagnetic Fe nanoparticles (≈3 nm) formed during conversion reaction to induce evolution of electrode magnetization between 0.01 and 1 V, during which spin‐polarized surface capacitance effect occurs at Fe/Na2S interfaces to increase extra ion storage and boost ion transport stably. Consequently, the FeS/C yolk‐shell nanosheets deliver a high reversible capacity of 664.9 mAh g−1 at 0.1 A g−1, and 300.4 mAh g−1 after 10 000 cycles at 10 A g−1 with a capacity retention of 81.1%. [ABSTRACT FROM AUTHOR]

Excessive carbon emissions will lead to catastrophic consequences such as global warming and rising oceans and will also have a serious negative impact on the human food supply and living environment. The steel industry is characterized by high pollution, and about 18% of China's carbon emissions come from the steel industry. The 'double carbon' strategy has brought important tasks and severe challenges to China's steel industry. With a view to evaluating the achievements of carbon emission control, carbon emission monitoring systems at home and abroad have been continuously established and improved. For the steel industry, accurate and efficient carbon monitoring technology has a guiding role in guiding energy conservation and carbon reduction. Traditional carbon emission accounting methods have some problems, such as long cycles and poor data quality, which restrict the improvement of the lean level of carbon emission monitoring management. Firstly, this paper investigates and analyzes the productive process and carbon emission process of the steel industry and constructs an entropy weight-grey correlation -TOPSIS analysis method for the correlation between carbon emissions and influencing factors. Based on the above content, a carbon emission monitoring method based on multiple influencing factors is put forward, and the high monitoring accuracy of the model is proved by taking the Tianjin steel industry as an example. The results show that information mining of relevant data can strikingly increase the accuracy of carbon emission monitoring in the steel industry. [ABSTRACT FROM AUTHOR]

The synthesis of high‐value fuels and plastics starting from small hydrocarbon molecules plays a central role in the current transition towards renewable energy. However, the detailed mechanisms driving the growth of hydrocarbon chains remain to a large extent unknown. Here we investigated the formation of hydrocarbon chains resulting from acetylene polymerization on a Ni(111) model catalyst surface. Exploiting X‐ray photoelectron spectroscopy up to near‐ambient pressures, the intermediate species and reaction products have been identified. Complementary in situ scanning tunneling microscopy observations shed light onto the C−C coupling mechanism. While the step edges of the metal catalyst are commonly assumed to be the active sites for the C−C coupling, we showed that the polymerization occurs instead on the flat terraces of the metallic surface. [ABSTRACT FROM AUTHOR]

Shared bikes as a public transport provide convenience for short-distance travel. Whilst they also act as a potential vector for antimicrobial resistant (AR) bacteria and antimicrobial resistance genes (ARGs). However, the understanding of the whole genome sequence of AR strains and ARGs-carrying plasmids collected from shared bikes is still lacking. Here, we used the HiSeq platform to sequence and analyze 24 Escherichia coli isolated from shared bikes around Metro Stations in Beijing. The isolates from shared bikes showed 14 STs and various genotypes. Two blaNDM-5 and blaCTX-M-199-producing ST167 E. coli have 16 resistance genes, four plasmid types and show >95% of similarities in core genomes compared with the ST167 E. coli strains from different origins. The blaNDM-5- or blaCTX-M-199-carrying plasmids sequencing by Nanopore were compared to plasmids with blaNDM-5- or blaCTX-M-199 originated from humans and animals. These two ST167 E. coli show high similarities in core genomes and the plasmid profiles with strains from hospital inpatients and farm animals. Our study indicated that ST167 E. coli is retained in diverse environments and carried with various plasmids. The analysis of strains such as ST167 can provide useful information for preventing or controlling the spread of AR bacteria between animals, humans and environments. [ABSTRACT FROM AUTHOR]

Lateral quantum confinement is of great interest in tuning the electronic properties of graphene‐based nanostructures, making them suitable for technological applications. In principle, these properties might be controlled through the edge topology: for example, zigzag nanoribbons are predicted to have spin‐polarized edge states. The practical realization of these structures is of utmost importance in fully harnessing the electronic properties of graphene. Here, the formation of regular, 1.4 nm wide ribbon‐like graphene structures with zigzag edges are reported, showing 1D electronic states. It is found that these "pseudo‐ribbons" embedded in single‐layer graphene supported on Ni(100) can spontaneously form upon carbon segregation underneath 1D graphene moiré domains, extending hundreds of nanometers in length. On the basis of both microscopy/spectroscopy/diffraction experiments and theoretical simulations, it is shown that these structures, even though seamlessly incorporated in a matrix of strongly interacting graphene, exhibit electronic properties closely resembling those of zigzag nanoribbons. [ABSTRACT FROM AUTHOR]

Spherical gold (Au) nanoparticles are formed onto glass surface by sputtering of Au foil and the following annealing process. By employing electric field assisted annealing of above as-prepared samples, the original spherical Au nanoparticles are dissolved to lunar-eclipselike structure and even fully dissolved. When applied voltages are increased in steplike feature, spikelike sharp current increase is observed at every voltage step, and it is followed by a rather long current decaying process. The spikelike current increase indicates the onset of electronic transport, leading to Au nanoparticles polarization and ionization. Long current decaying process is assigned to the electronic conduction from cathode to recombine with as-ionized positive charges, along with Au cationic transport resulting in dissolution of Au atoms from the nanoparticles. Our current study provides straightforward evidence of electric field assisted dissolution of Au nanoparticles on glass surface. [ABSTRACT FROM AUTHOR]

Dissolution of Au rods in gold-doped silicate glass is observed experimentally during the dc electric field thermal poling. Scanning electron microscopy characterizations show that some Au rods with a high aspect ratio are dissolved to spherelike particles and others still keep an elongated structure, which is well accorded with the absorption spectroscopy results. The mechanism for dissolution of Au particles is attributed to electron tunneling conduction and Au cationic conduction, based on electrical measurements during the electric field assisted dissolution process. Electric field thermal poling provides a promising method for the controlling of structural and optical properties of noble metal-doped silicate glass. [ABSTRACT FROM AUTHOR]