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81.
Estimates of Marcinkiewicz Integrals with Bounded Homogeneous Kernels of Degree Zero 总被引:2,自引:0,他引:2
Under the cancellation property and a certain Dini-type condition
on kernels, we prove that Marcinkiewicz integrals with kernels which are homogeneous
functions of degree zero, are bounded from
to
,
from
to
, and from
to
for
. 相似文献
82.
F. Semari F. Dahmane N. Baki Y. Al-Douri S. Akbudak G. Uğur Ş. Uğur A. Bouhemadou R. Khenata C.H. Voon 《Chinese Journal of Physics (Taipei)》2018,56(2):567-573
First-principles calculations were used to calculate the structural, electronic and half-metallic ferromagnetism of Mn2RuGe1-xSnx (x?=?0, 0.25, 0.50, 0.75, 1) Heusler alloys. The Hg2CuTi-type structure is found to be energetic more than Cu2MnAl-type structure for both Mn2RuGe and Mn2RuSn compounds. The calculated lattice constants for Mn2RuGe and Mn2RuSn are 5.91?Å and 6.17?Å, respectively. The electronic band structures and density of states of Mn2RuGe show a half metallic character with total magnetic moments, 2 μB per formula unit that are in good agreement with Slater-Pauling rule with indirect band gap, 0.31?eV along the direction Γ –X. It is observed that the total magnetic moment per cell increases as Sn concentration increases in the Heusler alloys. 相似文献
83.
Boo Rim Choe Hyungwoon Koo Wayne Smith 《Transactions of the American Mathematical Society》2003,355(7):2829-2855
We study the action of composition operators on Sobolev spaces of analytic functions having fractional derivatives in some weighted Bergman space or Hardy space on the unit disk. Criteria for when such operators are bounded or compact are given. In particular, we find the precise range of orders of fractional derivatives for which all composition operators are bounded on such spaces. Sharp results about boundedness and compactness of a composition operator are also given when the inducing map is polygonal.
84.
A large mode area photonic crystal fiber (LMA PCF) with an effective area of 180 μm2 is used to generate a high energy, micro-joule range, flat, octave spanning supercontinuum (SC) extending from ~ 600 nm to ~ 1720 nm. A train of femtosecond pulses from a widely-tunable parametric amplifier pumped by a Ti:Sapphire regenerative amplifier system are coupled into a 20 cm length of LMA PCF generating a SC of 1.4 μJ energy. We present an experimental study of the high energy SC as a function of the input power and the pumping wavelength. The spectrum obtained at a pump wavelength of 1260 nm presents spectral flatness variation less than 12 dB over more than 1.1 octave bandwidth. The physical processes behind the SC formation are described in the normal and the anomalous dispersion regions. Our experimental results are successfully compared with the numerical solution of the nonlinear Schrödinger equation. 相似文献
85.
Dr. Yahui Chen You Rim Lee Wenjing Wang Yu Fang Dr. Sheng Lu Dr. Jingjing Han Prof. Xiaoqiang Chen Prof. Myung Hwa Kim Prof. Juyoung Yoon 《Angewandte Chemie (International ed. in English)》2023,62(15):e202301765
Photoswitchable materials have attracted considerable attention in various fields. Developing excellent solid-state dual-mode photoswitches is an important but challenging task. Herein, we propose a new strategy to construct an excited-state intramolecular proton transfer (ESIPT) inspired photoswitch ( DiAH-pht ) that possesses aggregation-induced emission (AIE) features and displays a fast molecular isomerization process characterized by dual-mode behavior in the solid state. Mechanistic studies indicate that introduction of a bulky group can create a folded molecular conformation that provides adequate volume to facilitate photoisomerization and the enhanced ESIPT effect can boost the isomerization process. The feasibility of our strategy was further demonstrated by the activated photoisomerization performance of the Schiff base derivatives. Furthermore, DiAH-pht shows good performance in the fields of dual-mode information encryption and high-density data storage. 相似文献
86.
Robustness in Operations Research/Decision Aid is often associated with min–max and min–max regret criteria. This common approach to determine robust solutions consists in finding a solution which minimizes the maximal cost or regret. Nevertheless, these criteria are known to be too conservative. In this paper, we present and study a new robustness approach, called lexicographic α-robustness, which compensates for this major drawback and many others. Furthermore, we establish a link between lexicographic α-robustness and a third robustness approach called p-robustness. 相似文献
87.
Dr. Rim Makhoul Dr. Paul Hamon Dr. Thierry Roisnel Dr. Jean-René Hamon Dr. Claude Lapinte 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(38):8368-8371
The unprecedented tetrairon dication [{Cp*(dppe)FeC≡C-}4-μ-(1,2,4,5-C6H2)](PF6)2 ( 1 ) was obtained through a sequence of three reactions from 1,2,4,5-tetraethynylbenzene, Cp*(dppe)FeCl (Cp*=C5Me5, dppe=1,2-bis(diphenylphosphino)-ethane), KOtBu, and ferrocenium hexafluorophosphate. The cyclic voltammogram of the target molecule, isolated in 77 % yield, exhibits four well separated and reversible redox events showing that 1 is thermodynamically stable with respect to disproportionation (Kc>106). The tetranuclear dication 1 was characterized by XRD on single crystal, IR and NMR spectroscopies and Mössbauer spectrometry. The experimental data show that 1 behaves as a class II mixed-valence complex with the positive charges preferentially disposed on antipodal positions. This new molecule can be regarded as a potential molecular prototype of quantum dot cellular automata. 相似文献
88.
Nowadays, the environment protection and the personal health and safety are given more consideration in the field of chemistry, thus resulting in an increased number of published researches about how to work according to green instructions, to follow up the recommendations of environmental agencies and to obtain better clean handling of chemistry. In this review, green chemistry definition, importance, principles, and some recent applications in the field of green chemistry were discussed. In addition, the review summarizes the evolution of green analytical chemistry (GAC) with its specific principles and how to make the analytical process more environmentally benign with special emphasis on recent applications of GAC. Moreover, the green chromatography, its methods, and some of its applications were outlined. Finally, different techniques available up till now for the assessment of greening of the methods were also presented. 相似文献
89.
90.
Minjoong Yoon Jae Rim Chang Dongho Kim Yasunao Kuriyama Katsumi Tokumaru 《Photochemistry and photobiology》1991,54(1):75-82
The micellar dependencies of the photophysical properties of benoxaprofen (BXP), a 2-phenyl benzoxazole derivative, have been investigated using fluorescence spectroscopy and laser flash photolysis techniques. The fluorescence of BXP in aqueous solution has been observed to be remarkably quenched upon addition of a surfactant, cetyltrimethyl ammonium bromide (CTAB) or Triton X-100, in contrast to its enhancement in sodium dodecyl sulfate (SDS) micellar solution. Time-resolved fluorescence measurements show that the fluorescence decays biexponentially in the micellar solution, indicating the relaxation of micellar environments surrounding the excited BXP. The major component of fluorescence lifetimes in CTAB or Triton X-100 micellar phase is even shorter (330–427ps) than in SDS micellar phase (731 ps). The nonradiative decay constants are significantly larger (ca 3.0 times 109 s?1) in the CTAB or Triton X-100 micellar phase than in SDS micelles by a factor of ca 10. The major nonradiative decay is interpreted to be the internal conversion due to nuclear geometric change of BXP in the first excited singlet state. This is consistent with the observation that the quantum yields of intersystem crossing are very low (less than 0.01) in the micellar solutions as determined by the laser flash photolysis technique. The laser-induced transient absorption spectrum of BXP in CTAB or Triton X-100 micellar solution shows that the decay kinetics of the transients in CTAB or Triton X-100 are significantly different from first order kinetics in SDS. 相似文献