Boundedness for parabolic singular integral with rough kernels and its commutators on Triebel-Lizorkin spaces

In this paper, the authors give the boundedness on Triebel-Lizorkin spaces for the parabolic singular integral with rough kernel and its commutator.     

A simple solution-immersion process for the fabrication of superhydrophobic cupric stearate surface with easy repairable property

The present work reports a simple and time-saving method to fabricate cupric stearate film on zinc substrate by a solution-immersion process. Superhydrophobic surfaces are conventionally prepared employing two steps: roughening a surface and lowering its surface energy. The fabrication of superhydrophobic cupric stearate surface is reported using a one-step process by immersing a zinc plate coated with copper into the stearic acid solution, simplifying the complexity of two different steps involved in the conventional methods. The surface of the zinc plate coated with copper is found to be covered with low surface energy cupric stearate film providing the water contact angle of 160 ± 1° with the rolling off properties. In addition, the damaged superhydrophobic surface can restore superhydrophobicity property by immersing the surface into the stearic acid solution again.     

Superhydrophobic alumina surface based on stearic acid modification

A novel superhydrophobic alumina surface is fabricated by grafting stearic acid layer onto the porous and roughened aluminum film. The chemical and phase structure, morphology, and the chemical state of the atoms at the superhydrophobic surface were investigated by techniques as FTIR, XRD, FE-SEM, and XPS, respectively. Results show that a super water-repellent surface with a contact angle of 154.2° is generated. The superhydrophobic alumina surface takes on an uneven flowerlike structure with many nanometer-scale hollows distribute in the nipple-shaped protrusions, and which is composed of boehmite crystal and γ-Al₂O₃. Furthermore, the roughened and porous alumina surface is coated with a layer of hydrophobic alkyl chains which come from stearic acid molecules. Therefore, both the roughened structure and the hydrophobic layer endue the alumina surface with the superhydrophobic behavior.     

考虑意外事件对交通流影响的元胞自动机交通流模型

在NaSh模型的基础上,考虑交通事故和养护路段等意外事件对高速公路交通流的影响,建立了有意外事件影响的在车道管制下的高速公路交通流元胞自动机模型,并进行数值模拟. 研究发现:意外事件对高速公路交通流有明显影响,并且意外事件对交通流的影响在某一密度值范围内尤其明显,且意外事件堵塞点在第一车道比在第二车道对交通流的影响小;同时,在该密度值范围内,意外事件堵塞时间和堵塞路段长度越长,对交通流的影响就越大. 关键词： 元胞自动机 交通流 意外事件     

原子在红外激光场中产生高次谐波及阿秒脉冲随波长的变化规律

利用强场近似理论,研究了在长波红外激光场(波长800—2000 nm)驱动下氢原子产生的高次谐波,分析了在截止位置附近高次谐波的转换效率随激光波长的变化规律.发现在截止位置附近原子发射高次谐波的转换效率比平台区域的转换效率低,但获得的阿秒脉冲的宽度会随波长的增大而缩短. 关键词： 强场近似 高次谐波 阿秒脉冲     

名义组分为Y_6Ba_(11)Cu_(16)O_x的纳米超导材料

采用柠檬酸盐热分解法制备了名义组分为Y6Ba11Cu16Ox的纳米超导材料。利用XRD对其粉体进行物相表征,发现其相是Y123和Y211的混合相,并测得两者之间的摩尔比为1∶0.14,同时把其XRD图谱与Y1Ba2Cu3O7-x的XRD图谱进行了对照分析。利用标准的四端引线法对其块体进行R-T分析,测出其起始转变温度Tonset=86.0K,转变宽度△Tc=6.7K,并表现出良好的超导电性,也相应地把其与Y1Ba2Cu3O7-x进行了对比。根据Scherrer公式计算得到样品的平均晶粒尺寸约为67.1nm。文中也分析了所制材料为混合物的原因。     

一种改进的无链表3DSPITH算法用于高光谱图像压缩

 针对大孔径静态干涉成像光谱仪(LASIS)的成像特点,提出了一种基于三维非对称等长树小波变换的无链表SPITH算法结合ROI的图像压缩方案。首先,对干涉高光谱图像进行三维非对称等长树离散小波变换。其次,采用ROI方法对主要的光谱系数进行保护。最后,采用改进的三维无链表SPITH算法,编码干涉高光谱图像的小波变换域。实验结果表明,该方法在8∶1压缩比下,获得大于40 dB的平均峰值信噪比,同时有效地保护了光谱信息。     

Synthesis and photoluminescence of iridium complexes with benzothiazol-2-yl carbazole derivative ligand

Two new iridium(III) complexes containing benzothiazol-2-yl carbazole derivative as a cyclometalated ligand (L) and picolinate (pic) or acetylacetonate (acac) as the ancillary ligand, Ir(III) bis(3-(benzothiazol-2-yl)-9-butyl-carbazole)(picolinate) [Ir(L)₂(pic)] and Ir(III) bis(3-(benzothiazol-2-yl)-9-butyl-carbazole)(acetylacetonate) [Ir(L)₂(acac)], were synthesized and characterized by elemental analysis, ¹H NMR, FT-IR, and UV–Vis absorption spectra. Both the iridium(III) complexes emit intense green–yellow emissions, indicating that they are useful for the fabrication of organic light-emitting diodes.     

An efficient method for the preparation of 3-hydroxyl-5-substituted 2-pyrrolidones and application in the divergent synthesis of (−)-preussin and its analogues

An asymmetric method to (S,R)-α-hydroxyl-γ-amino alcohols 12 through a diastereoselective addition of Grignard reagents to β-chiral aldimines 11 is described. Subsequent oxidation/cyclization with Sarett reagent provided a novel approach to lactams 14, a flexible building block whose utility was demonstrated in the divergent synthesis of antifungal agent (−)-preussin 5 and its three analogues 23, 24, 25.     

FeCl3·6H2O oxidation of protected resveratrol for the synthesis of tetraarylfuran-type oligostilbenes

Several 8-8-coupled tetraarylfuran-type oligostilbenes were prepared through FeCl₃·6H₂O-catalyzed regioselective oxidative couplings of protected resveratrol precursors. The global deprotection of the coupling dimers in a one-pot reaction yielded (±)-pallidol instead of the targets (±)-restrytisol B and (±)-tricuspidatol A.