Hausdorff operators on the Heisenberg group

This paper is devoted to the high-dimensional and multilinear Hausdorff operators on the Heisenberg group H n. The sharp bounds for the strong type(p, p)(1 ≤ p ≤∞) estimates of n-dimensional Hausdorff operators on H n are obtained. The sharp bounds for strong(p, p) estimates are further extended to multilinear cases. As an application, we derive the sharp constant for the multilinear Hardy operator on H n. The weak type(p, p)(1 ≤ p ≤∞) estimates are also obtained.     

激波风洞信号测量仪

本文叙述了一种用于激波风洞实验研究中的以微机为基础的多功能智能测量仪表,叙述了其构成部分和性能、硬件结构和原理、软件编制以及将BASIC程序写入EPROM的过程。     

NOON State Generation with Phonons in Acoustic Wave Resonators Assisted by a Nitrogen‐Vacancy‐Center Ensemble

Since the quality factor of an acoustic wave resonator (AWR) reached 10¹¹, AWRs have been regarded as a good carrier of quantum information. In this paper, a scheme to construct a NOON state with two AWRs assisted by a nitrogen‐vacancy‐center ensemble (NVE) is proposed. The two AWRs cross each other vertically, and the NVE is located at the center of the crossing. By considering the decoherence of the system and using resonant interactions between the AWRs and the NVE, and the single‐qubit operation of the NVE, a NOON state can be achieved with a fidelity higher than 98.8% when the number of phonons in the AWR is $N\le 3$.     

Facile synthesis of Pd-decorated ZnO nanoparticles for acetone sensors with enhanced performance

ZnO and Pd nanoparticles (NPs) with average diameter of 38 and 10 nm were prepared in advance through a chemical solution method. Pd-functionalized ZnO nanoparticles (Pd@ZnO) were simply synthesized by adding ethanol solution of Pd NPs into ZnO powder, and annealing in argon atmosphere at 500 °C for 1 h after grinding for 30 min. The morphology and structure of the materials were systemically analyzed using Brunauer–Emmett–Teller (BET), X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM), and transmission electron microscopy (TEM) techniques. A weak peak in the XRD pattern of Pd@ZnO belonging to the (111) plane of elemental Pd indicated successfully loading of Pd. EDS and TEM results further confirmed successfully coating of Pd NPs onto the surface of ZnO. Sensors using ZnO NPs decorated with Pd (1 wt%) on the surface of exhibited highly elevated sensitivity of 76 in comparing with the response of 36 when based on pure ZnO NPs. In addition, such modification also resulted in a decrease in the operating temperature from 370 to 340 °C for 100 ppm acetone vapor. The sensing mechanism of the sensor based on Pd@ZnO NPs is discussed. Addition of Pd NPs can play an important role in improving the performance of gas sensors, including high sensitivity, good selectivity, and short response/recovery times.     

Catalyst‐Free Protocol for the Synthesis of Quinoxalines and Pyrazines in PEG

A facile and simple catalyst‐free protocol has been developed for the condensation of 1,2‐diketones with aromatic 1,2‐diamines in polyethylene glycol (PEG), providing quinoxaline derivatives in good yields. The important features of the methodology are broad substrates scope, simple workup, catalyst free, environmentally benign, and no requirement for metal catalysts. It is noteworthy that the cyclization reaction of 1,2‐diketones with aliphatic 1,2‐diamines is also conducted smoothly to afford pyrazines in good yields under the standard conditions. In addition, PEG could be recovered easily and was reused without evident loss in activity     

不同肋间胸腔闭式引流治疗胸腔积液的疗效分析

目的探讨不同肋间胸腔闭式引流治疗胸腔积液的疗效。方法收集信丰县人民医院2015年1月—2016年1月86例胸腔积液患者,按照入院顺序分成观察组与对照组,观察组经第5肋间实施胸腔闭式引流术,对照组经第6、7肋间实施胸腔闭式引流术,对比两组患者术后疼痛评分、临床疗效、胸水完全吸收时间、引流管留置时间、住院时间及并发症情况。结果观察组术后疼痛评分均低于对照组(P0.05);观察组总有效率高于对照组(P0.05);两组胸水完全吸收时间、胸腔引流管留置时间、住院时间对比无显著差异(P0.05);两组并发症发生率对比无显著差异(P0.05)。结论第5肋间的胸腔闭式引流术在胸腔积液的临床治疗中具有更好的效果,可缓解术后疼痛,值得临床应用。     

The Versatile Electronic,Magnetic and Photo-Electro Catalytic Activity of a New 2D MA2Z4 Family**

The recent successful growth of MoSi₂N₄ and WSi₂N₄ monolayers led to the discovery of a new class of the two-dimensional (2D) MA₂Z₄ materials with no known 3D layered allotropes, which renders great possibilities to integrate diverse properties by proper design of sandwiched “MZ₂” building blocks and “A−Z” passivation layers. In this work, the dynamic stability, electronic properties, and surface reactivity of the new MA₂Z₄ family, in which M is Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, W, A refers to Si or Ge, and Z is N, P or As, is theoretically probed. Among the proposed 54 possible combinations, about 42 compositions are dynamically stable, which vary from non-magnetic, anti-ferromagnetic, to ferromagnetic semiconductors, metals and half-metals. In particular, the VB (V, Nb, Ta) MA₂Z₄ possesses robust intrinsic ferromagnetism that is essential for spintronics applications. In regard to surface activity, most MA₂Z₄, particularly N- or P-terminated IVB and VB MA₂Z₄, have high catalytic potential for hydrogen evolution, and the ▵G_H of non-magnetic MA₂Z₄ is highly correlated to the highest occupied p electronic states of the surface Z atoms. The photocatalytic activity is also evaluated. MoSi₂N₄ and WSi₂N₄ within 4 % tensile strain are capable of photocatalytic overall water splitting. The findings indicate the new 2D MA₂Z₄ family has fascinating properties and possesses strong potential for applications but not limited to electronics, spintronics and catalysts, which will stimulate the interests of experimental synthesis.     

Goniodilactone and gomoheptenolactone,two novel cytotoxic styryllactones from the leaves of Goniothalamus cheliensis

Two novel styryllactones,goniodilactone（1） and gonioheptenolactone（2）,were isolated from the leaves of Goniothalamus cheliensis Hu.Their structures were determined on the basis of spectroscopic data as well as X-ray crystallography analysis. Compounds 1 and 2 exhibited significant cytotoxicities in a panel of human cancer cells,including DU-145,PC-3,MCF-7,A-549, KB and KBvin,with GI₅₀S in the range of 1.29-4.56μg/mL.     

质量控制图用于石墨炉原子吸收光谱法检测海水中铅元素

为保证海水中重金属检测结果的准确可靠,以铅元素为例,每个工作日使用石墨炉原子吸收光谱仪平行测定铅质控样2次,收集20组有效数据后,通过计算均值、标准差得出上下控制限、警告线及辅助限,绘制出在当前实验室环境条件、仪器设备、试剂药品和人员水平等因素条件下的质量控制图。该质量控制图不仅用于实际检测过程中对检测结果进行监控,还可为该实验室的人员考核、留样复测等实验室质量控制行为提供结果判定依据。