BOUNDEDNESS OF VECTOR-VALUED CALDERN-ZYGMUND OPERATORS ON HERZ SPACES WITH NON-DOUBLING MEASURES

In the paper we obtain vector-valued inequalities for Calder6n-Zygmund operator, simply CZO on Herz space and weak Herz space. In particular.we obtain vector-valued inequalities for CZO on Lq(Rd, |x|αdμ) space, with 1< q <∞, -n <α< n(q -1), and on L1,∞(Rd,|x|αdμ) space, with -n <α< 0.     

Reverse micellar synthesis and properties of nanocrystalline GMR materials (LaMnO3, La0.67Sr0.33MnO3 and La0.67Ca0.33MnO3): Ramifications of size considerations

Nanoparticles of complex manganites (viz. LaMnO₃, La_0.67Sr_0.33MnO₃ and La_0.67Ca{0.33}MnO₃) have been synthesized using the reverse micellar route. These manganites are prepared at 800‡C and the monophasic nature of all the oxides has been established by powder X-ray diffraction studies. TEM studies show an average grain size of 68, 80 and 50 nm for LaMnO₃, La_0.67Sr_0.33MnO₃ and La_0.67Ca{0.33}MnO₃respectively. Ferromagnetic ordering is observed at around 250 K for LaMnO₃, 350 K for La_0.67Sr_0.33MnO₃ and 200 K for La_0.67Ca{0.33}MnO₃. These Curie temperatures correspond well with those reported for bulk materials with similar composition.     

关于极大$S^2NS$阵的一个注记

一个实方阵A称为是S2NS阵,若所有与A有相同符号模式的矩阵均可逆,且它们的逆矩阵的符号模式都相同．若A是S2NS阵且A中任意一个零元换为任意非零元后所得的矩阵都不是S2NS阵,则称A是极大S2NS阵．设所有n阶极大S2NS阵的非零元个数所成之集合为S(n),Z4(n)={1/2n(n-1) 4,…,1/2n(n 1)-1},除了2n 1到3n一4间的一段和Z4(n)外,S(n)得到了完全确定．本文将用图论方法证明Z4(n)∩S(n)=(?)．     

Bio-regeneration of p-complexation desulfurization adsorbents

More and more stringent regulations of gasoline and diesel oil were proposed with the awareness of environmental protection. Hydrodesulfurization (HDS) is a conventional method to remove sulfur compounds for industrial purpose. The main drawbacks of this …     

Photocatalytic Synthesis of Oxygenates from Gaseous CO2 and CH4 over Semiconductor

Photoinduced synthesis of CO2 and CH4 was investigated using a batch reaction system on several photoactive materials supported on silicon dioxide. Single semiconductor showed higher selectivity to C1 compounds. The production of C2-C3 oxygenates took place preferentially on composite semiconductor photocatalysts. In particular, it was found that acetone was the primary product over Cu/CdS-TiO2/SiO2.     

内源全息术的原理和数学描述

以往的全息术在对原子成像时,在相干光源、探测器空间分辨和信号强度三个方面遇到了难以克服的困难. 阐述了内源全息术克服这些困难的原理,研究了内源全息术的记录和再现全过程,推导出内源球面全息图的再现公式,并在散射因子球对称近似和能量无关近似下,推导出以δ函数表示原子全息再现像的解析表达式. 关键词： 内源全息术 同步辐射 晶体结构 傅里叶变换     

An Efficient, One-Pot Synthesis of Carbamates from the Corresponding Alcohols Using Mitsunobu’s Reagent

A novel Mitsunobu-based protocol was developed for the synthesis of carbamates from the corresponding alcohols using carbon dioxide and amines in good to excellent yields. This protocol is mild, chemoselective, and efficient compared to other reported methods.     

Adsorption of dicarboxylates on nano-sized gibbsite particles: effects of ligand structure on bonding mechanisms

The adsorption of the dicarboxylates o-phthalate, maleate, fumarate, malonate, and oxalate (representing ligands with the general composition ⁻O₂C---C_n---CO₂⁻; n=0, 1, or 2) on gibbsite were studied by means of quantitative batch adsorption experiments and attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The interpretations of ATR-FTIR spectra were aided by comparison with IR spectra of solution species and by results from theoretical frequency calculations. The main objectives of the study were to identify the molecular level bonding mechanisms of the dicarboxylates to gibbsite, and to investigate how these were influenced by the composition and structure of the ligands. Carboxylates with n=2 formed predominantly outer sphere complexes, whereas the importance of inner sphere complexes progressively increased for n=1 and 0. The inner sphere structures were identified as mononuclear chelates with one oxygen from each carboxylate group bonded to Al(III) at the surface. This showed the importance of chelate ring structure for the formation of inner sphere surface complexes, with stabilities of the complexes increasing in the order seven-membered ring less than six-membered ring less than five-membered ring. For ligands with n=2 only small variations in surface speciation were observed as a function of steric factors; irrespective of the relative positions of the carboxylate groups and bulkiness of the ligands outer sphere bonding is the dominating adsorption mode. Adsorption experiments were also conducted with gibbsite particles exhibiting differences in shape and surface roughness. These experiments showed that inner sphere complexes were favored on the less well-developed and more irregular gibbsite particles.