Water radical cations, the crucial intermediates in many aqueous reactions and biochemical processes, are difficult to be experimentally investigated due to its short lifetime and low abundance. Herein, a homemade device based on energy-tunable discharge was employed to deposit suitable amounts of energy to atmospheric pressure pure water vapor for abundant production of water radical cations, which were stabilized as (H 2 O) n +• (n=2-5) with the maximal abundance (≥ 8.3×10 6 cps) for (H 2 O) 2 +• as characterized by mass spectrometry (MS).The abundance of water radical cations was optimized by adjusting the experimental parameters such as discharge voltage (2.5 kV), temperature of the MS inlet (140 o C), carrier gas flow (20 mL/min) and the distance between the discharge tip and the MS inlet (12 mm). The ambient formation of water radical cations was further confirmed by the high reactivity of the as-prepared water radical cations, which instantly reacted with benzene, ethyl acetate and dimethyl disulfide, showing rich chemistry with the ionic and radical characters. Moreover, the computations confirm that the O-O single-electron bound dimer (B) as well as the hydronium hydroxyl radical complex (A) accounts for the unusual chemistry of the water radical cations, providing a facile approach to access the high reactivity of water radical cations under the ambient condition.

Most double-stranded RNA (dsRNA) viruses transcribe RNA plus strands within a common innermost capsid shell. This process requires coordinated efforts by RNA-dependent RNA polymerase (RdRp) together with other capsid proteins and genomic RNA. Here we report the near-atomic resolution structure of the RdRp protein VP2 in complex with its cofactor protein VP4 and genomic RNA within an aquareovirus capsid using 200-kV cryoelectron microscopy and symmetry-mismatch reconstruction. The structure of these capsid proteins enabled us to observe the elaborate nonicosahedral structure within the double-layered icosahedral capsid. Our structure shows that the RdRp complex is anchored at the inner surface of the capsid shell and interacts with genomic dsRNA and four of the five asymmetrically arranged N termini of the capsid shell proteins under the fivefold axis, implying roles for these N termini in virus assembly. The binding site of the RNA end at VP2 is different from the RNA cap binding site identified in the crystal structure of orthoreovirus RdRp λ3, although the structures of VP2 and λ3 are almost identical. A loop, which was thought to separate the RNA template and transcript, interacts with an apical domain of the capsid shell protein, suggesting a mechanism for regulating RdRp replication and transcription. A conserved nucleoside triphosphate binding site was localized in our RdRp cofactor protein VP4 structure, and interactions between the VP4 and the genomic RNA were identified.

The properties of nanomaterials are highly dependent on their size, shape and composition. Compared with zero-dimensional nanoparticles, the increased dimension of a one-dimensional silver nanowire (AgNW/Ag NW) leads to extra challenges on synthesizing it with controllable sizes. Here, a convenient way for the synthesis of AgNWs with tunable sizes has been developed simply by adjusting the amount of salt additives, i.e., ferric chloride (FeCl), or Fe(NO) & KCl. The average diameter and length of nanowires are readily tailored within 45-220 nm and 10-230 μm, respectively. The distinctive roles of Fe and Cl played during the growth stages of Ag NWs were revealed by comparative experiments and a heterogeneous nucleation model with the assistance of oxidative etching was proposed to elucidate the growth mechanism. Afterwards, transformations in XRD patterns from nanometer-size effects and quantitative relation for size-dependent peak wavelength of surface plasmon resonances (SPRs) in UV-vis spectroscopy of these nanowires were studied. In addition, as transparent conductive materials (TCMs), these metal nanowires were utilized to fabricate transparent conductive films (TCFs), and the effects of their diameters and lengths were elucidated. Very/ultra-long nanowires with a high aspect ratio up to 1600 achieved impressive properties of R = 12.4 ohm sq at T% = 90.1% without any post treatment. This facile method for the size-tunable growth of uniform AgNWs with high yield is attractive and ready to be home-made, which is believed to promote research in their potential applications, especially in optoelectronic devices and flexible electronics.

Light absorption of graphene plays an important role in optoelectronic applications. In this work, a series of reduced graphene oxide (RGO) dispersions containing flakes with various configurations are prepared, and their optical absorption coefficients are investigated. Our results suggest that the lateral size distribution, the mean number of layers per flake and the functional groups on RGO are all important factors influencing the absorption coefficient. We find the dispersion with a larger amount of small flakes (≤600 nm), as well as less layers per flake, gives a smaller absorption coefficient at 660 nm. Essentially, functional groups grafted on graphene flakes promote an eminent role in the absorption coefficient.

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At present, the preparation of highly porous graphitic activated carbons (HPGACs) using the usual physical and chemical activation methods has met a bottleneck. In this study, HPGACs are directly synthesized from lignite at 900 °C. The whole process is completed by a microwave pretreatment, a graphitization conversion of the carbon framework at a low temperature using a small amount of FeCl3 (10–30 wt%), and a subsequent physical activation using CO2. Consequently, the dispersed and mobile iron species, in the absence of oxygen functional groups (removed during the microwave pretreatment), can greatly promote catalytic graphitization during pyrolysis, and, as an activating catalyst, can further facilitate the porosity development during activation. The as-obtained AC-2FeHLH-5-41.4(H) presents a low defect density, high purity, and specific surface area of 1852.43 m2 g−1, which is far greater than the AC-HLH-5-55.6(H) obtained solely by physical activation. AC-2FeHLH-5-41.4(H) as a supercapacitor electrode presents an excellent performance in the further electrochemical measurements. Such a convenient and practical method with low cost proves a scalable method to prepare HPGACs from a wide range of coal/biomass materials for industrial scale-up and applications.

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A negative triggered lightning involving five types of leaders was recorded by high-speed camera using frame rate of 20,000 fps and fast antennas at different distances. Five types of leaders contained one upward positive stepped leader, one upward positive dart leader, ten downward negative dart leader, one bidirectional leader and three downward negative dart-stepped leaders were propagated successively in the same channel. The upward positive dart leader occurred after initial continuous current pulse with average 2-D speed of 1.40 × 106 m/s and started second continuous current process. The bidirectional leader was transformed from decaying unidirectional leader and showed the unique electric field changes. Faster return strokes are found to be induced by downward leaders propagating evenly and deposit more positive charge in the following residual channel. The positive charge can inhibit the potential initiation of an upward positive leader and boost the propagation of the next downward negative leader.