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排序方式: 共有245条查询结果,搜索用时 15 毫秒
91.
M. Agop Camelia Popa Anca Harabagiu 《理论物理通讯》2008,50(11):1197-1204
Considering the fractal structure of space-time, the scale relativity theory in the topological dimension DT = 2 is built. In such a conjecture, the geodesics of this space-time imply the hydrodynamic model of the quantum mechanics. Subsequently, the gauge gravitational field on a fractal space-time is given. Then, the gauge group, the gauge-covariant derivative, the strength tensor of the gauge field, the gauge-invariant Lagrangean, the field equations of the gauge potentials and the gauge energy-momentum tensor are determined. Finally, using this model, a Reissner- Nordstrom type metric is obtained. 相似文献
92.
Anca Radulescu 《Journal of statistical physics》2008,130(2):373-385
This paper adds a computational approach to a previous theoretical result illustrating how the complexity of a simple dynamical
system evolves under deformations. The algorithm targets topological entropy in the 2-dimensional family P
Q
of compositions of two logistic maps. Estimation of the topological entropy is made possible by the correspondence between
P
Q
and a subfamily of sawtooth maps P
T
, and is based on the well-known fact that the kneading-data of a map determines its entropy. A complex search for kneading-data
in P
T
turns out to be computationally fast and reliable, delivering good entropy estimates. Finally, the algorithm is used to produce
a picture of the entropy level-sets in P
Q
, as illustration to theoretical results such as Hu (Ph.D. thesis, CUNY, 1995) and Radulescu (Discrete Cont. Dyn. Syst. 19(1):139–175, 2007). 相似文献
93.
Anca Suteanu-Simulescu Alina Diana Zamfir Raluca Ica Mirela Sarbu Cristian V. A. Munteanu Florica Gadalean Adrian Vlad Flaviu Bob Dragos Catalin Jianu Ligia Petrica 《Molecules (Basel, Switzerland)》2022,27(9)
Considering the valuable information provided by glycosphingolipids as molecular markers and the limited data available for their detection and characterization in patients suffering from Type 2 diabetic kidney disease (DKD), we developed and implemented a superior method based on high-resolution (HR) mass spectrometry (MS) and tandem MS (MS/MS) for the determination of gangliosides in the urine of DKD patients. This study was focused on: (i) testing of the HR MS and MS/MS feasibility and performances in mapping and sequencing of renal gangliosides in Type 2 DM patients; (ii) determination of the changes in the urine gangliosidome of DKD patients in different stages of the disease—normo-, micro-, and macroalbuminuria—in a comparative assay with healthy controls. Due to the high resolution and mass accuracy, the comparative MS screening revealed that the sialylation status of the ganglioside components; their modification by O-acetyl, CH3COO−, O-fucosyl, and O-GalNAc; as well as the composition of the ceramide represent possible markers for early DKD detection, the assessment of disease progression, and follow-up treatment. Moreover, structural investigation by MS/MS demonstrated that GQ1d(d18:1/18:0), GT1α(d18:1/18:0) and GT1b(d18:1/18:0) isomers are associated with macroalbuminuria, meriting further investigation in relation to their role in DKD. 相似文献
94.
95.
Anca Visinescu 《Physics letters. A》1994,190(5-6):425-428
The three soliton contribution to the specific heat of a classical easy-plane ferromagnet chain is calculated using asymptotic methods from the theory of differential equations depending on a large parameter. 相似文献
96.
Simona M. Coman Anca Dobre Mircea D. Banciu Aurica Petride Valentin Cimpeanu Georges Poncelet Vasile I. Parvulescu 《Journal of molecular catalysis. A, Chemical》2004,220(2):257-265
Ru–BEA catalysts with 1.0–2.5 wt.% Ru were prepared by ion exchange. The acidic properties of these catalysts were investigated using deuterated acetonitrile, pyridine, and 2,6-di-tert-butyl-pyridine. The deposited Ru was studied by CO-FTIR spectroscopy. The materials were tested as catalysts in the hydrogenation of a conjugated cyclic keto–enol, namely, 5-hydroxymethylene-5H-6,7-dihydrodibenzo[a,c]cyclohepten-6-one. Beside hydrogenation, hydrogenolysis products were identified by GC–MS and 1H NMR techniques. Relations were sought between the selectivity and some physicochemical properties of the catalyst. 相似文献
97.
Artificial metalloenzymes, based on the incorporation of a catalytically active organometallic moiety within a host protein, lie at the interface between organometallic and enzymatic catalysis. In terms of activity, reaction repertoire, substrate range and operating conditions, they take advantage of the versatility of the organometallic chemistry. In contrast, the enantioselectivity is determined by the biomolecular scaffold, which provides a well defined second coordination sphere to the organometallic moiety, reminiscent of enzymes. The attractive feature of such systems is their optimization potential, which combines chemical and genetic methods (i.e. chemogenetic) to screen diversity space. This feature article describes the implementation of such an optimization protocol for artificial transfer hydrogenases, for which we have the most detailed understanding. 相似文献
98.
A new immunoassay strategy for sensitive atrazine determination based on magnetic beads is reported. The immuno-method is a competitive solid-phase immunoassay where the anti-atrazine antibody is immobilized on the magnetic beads surface and fixed at the reaction cell bottom using a simple magnet, which generates a magnetic field. Analyte and HRP (horseradish peroxidase) tracer compete for active sites of antibody. After the immunointeractions antibody-analyte and antibody-tracer, atrazine quantification from the sample is performed by injection of the chemiluminescence substrate (luminol, hydrogen peroxide and p-iodophenol). Different antibodies (polyIgG anti-atrazine Ab I and affinity purified polyIgG anti-atrazine AbI) were tested in this configuration. Also, optimum concentration of antibody-covered magnetic beads was set up (8 mg/l Ab II). Finally, the performance of magnetic beads-based immunoassay for atrazine determination was evaluated demonstrating that the magnetic beads-based immunoassay is one of the most sensitive method for atrazine determination (LoD = 3 pg/l, IC50 = 37 pg/l, DR = 10-1000 pg/l). 相似文献
99.
In this study the electron beam (e-beam) radiation synthesis in “paste-like condition” and characterization of the network structure of acrylic acid (AA) sodium salt/xanthan gum (XG)/carboxymethylcellulose (CMC) superabsorbent hydrogels incorporating graphene oxide (GO) was investigated. The effects of the AA concentration on gel fraction, sol-gel analysis, swelling degree and network parameters, as well as the relationship between these parameters and radiation dose was also established.Gel fraction exceeds 90%, and the p0/q0 ratio shows a moderate degradation process. The swelling kinetic data were used to determine, first the swelling degree, second the diffusion characteristics, and third the average molecular weight between crosslinks (Mc), as well as. The diffusion data revealed a Fickian mechanism transport, for each hydrogel compositions. The network parameters (Mc and ξ) increased with absorbed dose, while cross-linking density and the radiation-chemical yields were decreased. 相似文献
100.