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161.
Cornelis V. M. van der Mee André C. M. Ran Leiba Rodman 《Integral Equations and Operator Theory》2002,44(1):50-70
Polar decompositions with respect to an indefinite inner product are studied for bounded linear operators acting on a
space. Criteria are given for existence of various forms of the polar decompositions, under the conditions that the range of a given operatorX is closed and that zero is not an irregular critical point of the selfadjoint operatorX
[*]X. Both real and complex spaces
are considered. Relevant classes of operators having a selfadjoint (in the sense of the indefinite inner product) square root, or a selfadjoint logarithm, are characterized.The work of this author was partially supported by INdAM-GNCS and MURSTThe work of this author was partially supported by NSF grant DMS-9988579. 相似文献
162.
We demonstrate here the thermochemical hole burning (THB) effect on a series of N-substituted morpholinium 7,7,8,8-tetracyanoquinodimethane charge-transfer (C-T) complexes for ultra-high-density data storage. A correlation between the decomposition temperature of the charge-transfer complex and the threshold voltage of hole burning was observed: the higher the decomposition temperature, the larger the writing threshold value, suggesting the possibility of molecular design for optimizing the hole burning performance. The macroscopic decomposition properties of these charge-transfer complexes were studied by thermal gravimetry combined with mass spectrometry. Theoretical estimation of the temperature rise induced by scanning tunneling microscopy current heating was also conducted, which indicated that the maximum temperature certainly exceeds the decomposition temperatures of these C-T complexes. These observations are consistent with the thermochemical hole burning mechanism. 相似文献
163.
L.?Dai G.Z.?Ran J.C.?Zhang X.F.?Duan W.C.?Lian G.G.?QinEmail author 《Applied Physics A: Materials Science & Processing》2004,79(1):139-142
We have studied the influence of C and Si ion implantation with different implantation doses on yellow luminescence (YL) from GaN. Three kinds of GaN samples were used. In their as-grown states, #1 samples had strong YL, #2 samples had no YL, while #3 samples had weak YL. Our experimental results show that: (i) after annealing at 950 °C, the YL intensity for Si ion implanted #1 sample decreased with increasing implantation dose, while that for C ion implanted #1 sample exhibited a reverse rule; (ii) for #2 samples, C ion implantation produced much stronger YL than Si ion implantation did after annealing at 950 °C; (iii) the YL intensity sequence for Si ion implanted and 950 °C annealed #1, #2, and #3 samples was consistent with that for the unimplanted #1, #2, and #3 samples. However, the YL intensity sequence for the C ion implanted and 950 °C annealed #1, #2, and #3 samples reversed with that for the unimplanted ones. In order to explain all these phenomena, we suggested a physical model which claims that the deep C center is another important origin of YL in GaN, and during C ion implantation, the C ion prefers to combine with a VGa to form a CGa. PACS 78.55.-m, 85.40.Ry, 68.55.Ln 相似文献
164.
Lee KJ Kim HA Kim PH Lee HS Ma KR Park JH Kim DJ Hahn JH 《Experimental & molecular medicine》2004,36(6):534-544
During chronic inflammatory response, mono- cytes/macrophages produce 92-kDa matrix metalloproteinase-9 (MMP-9), which may contribute to their extravasation, migration and tissue remodeling. Activation of peroxisome proliferator- activated factor receptor-g (PPAR-g) has been shown to inhibit MMP-9 activity. To evaluate whether ox-LDL, a PPAR-g activator, inhibits PMA-induced MMP-9 expression and activity, and if so, whether CD36 and PPAR-g are involved in this process, we investigated the effect of ox-LDL on MMP-9 expression and activity in PMA-activated human monocytic cell line U937. PMA-induced MMP-9 expression and activity were suppressed by the treatment with ox-LDL (50 mg/ml) or PPAR-g activators such as troglitazone (5 mM), ciglitazone (5 mM), and 15d- PGJ2 (1 mM) for 24 h. This ox-LDL or PPAR-g activator-mediated inhibition of MMP-9 activity was diminished by the pre-treatment of cells with a blocking antibody to CD36, or PGF2a (0.3 mM), which is a PPAR-g inhibitor, as well as overexpression of a dominant-negative form of CD36. Taken together, these results suggest that ox-LDL suppresses PMA-induced MMP-9 expression and activity through CD36-mediated activation of PPAR-g. 相似文献
165.
This study addresses a fundamental challenge posed by hexavalent iron electrochemical irreversibility, which had slowed practical development of reversible Fe(VI) cathodes; nanolayers circumvent fundamental passivation challenges, and are electrodeposited from solution phase FeO(4)(2-), forming 601 mAh g(-1) Li, and 485 mAh g(-1) Na, Fe(III/VI) alkaline cathodes, the latter exhibiting 100-200 storage cycles at 80% depth of discharge, providing pathways towards metal hydride batteries with twice the cathode capacity. 相似文献
166.
Chen Cs Ran S Liu W Yang Ph Peng Dk Bouwmeester HJ 《Angewandte Chemie (International ed. in English)》2001,40(4):784-786
167.
In this paper we present an inertia result for Stein equations with
an indefinite right hand side. This result is applied to establish connnections
between the inertia of invertible hermitian block Toeplitz matrices and associated
orthogonal polynomials. 相似文献
168.
We propose a new image encryption algorithm based on a generalized fractional Fourier transform, to which we refer as a multifractional Fourier transform. We encrypt the input image simply by performing the multifractional Fourier transform with two keys. Numerical simulation results are given to verify the algorithm, and an optical implementation setup is also suggested. 相似文献
169.
We propose a Mach-Zehnder interferometer (MZI) based on coupled dielectric pillars. It is composed of single-row pillar coupled waveguide modulating arms and three-row pillar waveguide 3 dB couplers. The slow light property and transmission loss of the single-row pillar modulating arm are optimized by the plane wave expansion method. A short 3dB coupler is designed based on the modes transformation in three-row pillar waveguide. Finite difference time domain simulations prove the validity of this MZI and show that it has low insertion loss of 1.1 dB and high extinction ratio of 〉 12 dB. 相似文献
170.
Ran Zeng 《Optics Communications》2007,271(1):162-168
Nonclassical features of the superposition of two coherent states which are π/2 out of phase are discussed, such as sub-Poissonian photon statistics and quadrature squeezing, as well as negativity of the Wigner function. Special nonclassicality is found in the special state where the relative phase of superposition has relationship with the average photon number. The analysis of the amount of entanglement is also presented for the related two-mode entangled coherent states. 相似文献