Structural,magnetic and optical properties of vanadium doped zinc oxide: Systematic first-principles investigations

The electronic structural, magnetic and optical properties of pure and V-doped ZnO are investigated by first-principles calculations based on the density functional theory. With the introduction of V atoms, the spin-splitting near the Fermi level leads to a net magnetic moment of the system. A significant possibility of room temperature ferromagnetism (RTFM) originated from the Ruderman–Kittel–Kassuya–Yosida (RKKY) exchange is predicted. Oxygen vacancy is positive to enhance the ferromagnetism while zinc vacancy is negative. With respect to the optical properties, the presence of V atoms was found to have an obvious influence on the transmittivity, especially in the low energy region. A slight V-doping can keep a high optical transmission and smoothly modulate the optical bandgap.     

Design of a small-sized expanded coaxial line antenna at L-band

为了减小常规L波段高功率微波测量接收天线的结构尺寸及增益,设计了一种基于轴向缝隙馈电的小型化同轴扩张型天线.通过理论分析和数值模拟,选择了较优的结构尺寸,得到天线的增益及方向图特性:在1.3～1.6 GHz范围内,增益从-2.0 dBi变化至0.8 dBi；天线最大辐射方向在物理结构轴向.基于矢量网络分析仪E8362B的天线特性测量结果与数值计算结果基本一致:工作频率从1 3～1 6GHz变化时,增益从-2.3 dBi变化至1.2 dBi；E面方向图主瓣宽度大于 60°,轴向轴比大于35dB,结果表明设计的天线能够满足L波段高功率微波渊量天线低增益小型化要求.     

Facile Fabrication of Well‐Dispersed Pt Nanoparticles in Mesoporous Silica with Large Open Spaces and Their Catalytic Applications

In this paper, a facile strategy is reported for the preparation of well‐dispersed Pt nanoparticles in ordered mesoporous silica (Pt@OMS) by using a hybrid mesoporous phenolic resin‐silica nanocomposite as the parent material. The phenolic resin polymer is proposed herein to be the key in preventing the aggregation of Pt nanoparticles during their formation process and making contributions both to enhance the surface area and enlarge the pore size of the support. The Pt@OMS proves to be a highly active and stable catalyst for both gas‐phase oxidation of CO and liquid‐phase hydrogenation of 4‐nitrophenol. This work might open new avenues for the preparation of noble metal nanoparticles in mesoporous silica with unique structures for catalytic applications.     

Efficient Synthesis of Spirooxindole Pyrrolones by a Rhodium(III)‐Catalyzed C−H Activation/Carbene Insertion/Lossen Rearrangement Sequence

A rhodium(III)‐catalyzed domino annulation of simple olefins with diazo oxindoles to give spirooxindole pyrrolone products is described. This reaction can be formally viewed as the result of an anomalous tandem C?H activation, carbene insertion, Lossen rearrangement, and a nucleophilic addition process. The potential utility of this reaction was further demonstrated by the late‐stage diversification of drug molecules.     

Pharmacokinetics of salvianolic acid B,rosmarinic acid and Danshensu in rat after pulmonary administration of Salvia miltiorrhiza polyphenolic acid solution

A sensitive and accurate LC–MS/MS method was established for quantifying salvianolic acid B (Sal B), rosmarinic acid (Ros A) and Danshensu (DA) in rat plasma. Salvia miltiorrhiza polyphenolic acid (SMPA), active water‐soluble ingredients isolated and purified from Salvia miltiorrhiza Bge included Sal B, Ros A and DA. The pharmacokinetic analysis of Sal B, Ros A and DA after pulmonary administration of SMPA solution to rat was performed by LC–MS/MS. Results from the pharmacokinetic studies showed that the peak concentration of DA was 21.85 ± 6.43 and 65.39 ± 3.83 ng/mL after pulmonary and intravenous administration, respectively. DA was not detected at 2 h after administration. The absolute bioavailabilities of Sal B and Ros A were respectively 50.37 ± 27.04 and 89.63 ± 12.16% after pulmonary administration of 10 mg/kg SMPA solution in rats. The absolute bioavailability of Sal B increased at least 10‐fold after pulmonary administration, compared with oral administration. It was concluded that the newly established LC–MS/MS method was suitable for describing the pharmacokinetic characteristics of Sal B, Ros A and DA in rat after pulmonary administration of SMPA solution. The data from this study will provide a preclinical insight into the feasibility of pulmonary administration of SMPA.