To construct more desirable adsorption affinity between the current metal−organic frameworks and benzothiophene (BT), a novel desulfurizer (V/Cu−BTC, where BTC represents 1,3,5-benzenetricarboxylic acid) was prepared by reducing Cu(II) to Cu(I) with V(III) on Cu−BTC using a hydrothermal synthesis method. Using nitrogen adsorption− desorption, powder X-ray diffraction, scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy, we approved that the modifications of those novel desulfurizers have been successfully realized and further compared their structural changes. The BT capture performance from the different simulated fuels with V/Cu−BTC was evaluated by batch tests. The results manifest that V/Cu−BTC exhibited impressive desulfurization capacity, which is grander to Cu−BTC and some other adsorbents reported previously. Additionally, as a result of sieving and inertia mechanisms, this adsorbent possessed an extremely high affinity for BT capture in the presence of benzene. V/Cu−BTC showed a remarkable stability in BT adsorption, maintaining more than 90% initial sulfur uptake capacity after 5 regeneration times. In general, the V/ Cu−BTC material is very beneficial for the adsorptive removal of BT.

Dirac materials exhibit intriguing low-energy carrier dynamics that offer a fertile ground for novel physics discovery. Of particular interest is the interplay of Dirac carriers with other quantum phenomena such as magnetism. Here we report on a two-magnon Raman scattering study of AMnBi2 (A=Ca, Sr), a prototypical magnetic Dirac system comprising alternating Dirac carrier and magnetic layers. We present the first accurate determination of the exchange energies in these compounds and, by comparison with the reference compound BaMn2Bi2, we show that the Dirac carrier layers in AMnBi2 significantly enhance the exchange coupling between the magnetic layers, which in turn drives a charge-gap opening along the Dirac locus. Our findings break new grounds in unveiling the fundamental physics of magnetic Dirac materials, which offer a novel platform for probing a distinct type of spin–Fermion interaction. The results also hold great promise for applications in magnetic Dirac devices.

Small interplanetary magnetic flux ropes (SIMFRs) are commonly observed by spacecraft at 1 AU, and their origin still remains disputed. We investigated the counterstreaming suprathermal electron (CSE) signatures of 106 SIMFRs measured by Wind during 1995–2005. We found that 79 (75%) of the 106 flux ropes contain CSEs, and the percentages of counterstreaming vary from 8% to 98%, with a mean value of 51%. CSEs are often observed in magnetic clouds (MCs), and this indicates these MCs are still attached to the Sun at both ends. CSEs are also related to heliospheric current sheets (HCSs) and the Earth's bow shock. We divided the SIMFRs into two categories: The first category is far from HCSs, and the second category is in the vicinity of HCSs. The first category has 57 SIMFRs, and only 7 of 57 ropes have no CSEs. This ratio is similar to that of MCs. The second category has 49 SIMFRs; however, 20 of the 49 events have no CSEs. This ratio is larger than that of MCs. These two categories have different origins. One category originates from the solar corona, and most ropes are still connected to the Sun at both ends. The other category is formed near HCSs in the interplanetary space.

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Electromagnetic cyclotron waves (ECWs) near the proton cyclotron frequency are frequently observed in the solar wind, yet their generation mechanism is still an open question. Based on the Wind data during the years 2005−2015, this paper carries out a statistical study on plasma characteristics associated with the occurrence of ECWs. The probability density distributions (PDDs) of proton temperature anisotropy (T ⊥ /T ) and proton parallel beta (β ) are investigated,where ⊥ and refer to perpendicular and parallel to the background magnetic field, respectively. The PDDs depend on solar wind types as well as wave polarizations, and those for ECWs with left-handed (LH) polarization exhibit considerable differences from the PDDs for ambient solar winds. The distributions of occurrence rates of LH ECWs in (β , T ⊥ /T ) space show a tendency that the occurrence rates increase with proton temperature anisotropies. The β with maximum of occurrence rates is near 0.1 when T ⊥ /T > 1 while it is around 1 when T ⊥ /T < 1. The presence of alpha−proton differential flow with large kinetic energy corresponds to a much high occurrence rate as well as the domination of LH polarization of ECWs. Based on these observations and existing theories, we propose that the proton cyclotron and parallel firehose instabilities with effects of alpha−proton differential flow are likely responsible for the local generation of LH ECWs in the solar wind. The generation mechanism of righthanded ECWs seems to be complicated and more discussions are needed in future researches.