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31.
32.
The paper presents a quantitative explanation of failure of generic Monte Carlo techniques as applied to optimization problems of high dimensions. Deterministic grids are also discussed. 相似文献
33.
Cassandra Millet-Boureima Roman Rozencwaig Felix Polyak Chiara Gamberi 《Molecules (Basel, Switzerland)》2020,25(22)
Autosomal dominant polycystic kidney disease (ADPKD) causes progressive cystic degeneration of the renal tubules, the nephrons, eventually severely compromising kidney function. ADPKD is incurable, with half of the patients eventually needing renal replacement. Treatments for ADPKD patients are limited and new effective therapeutics are needed. Melatonin, a central metabolic regulator conserved across all life kingdoms, exhibits oncostatic and oncoprotective activity and no detected toxicity. Here, we used the Bicaudal C (BicC) Drosophila model of polycystic kidney disease to test the cyst-reducing potential of melatonin. Significant cyst reduction was found in the renal (Malpighian) tubules upon melatonin administration and suggest mechanistic sophistication. Similar to vertebrate PKD, the BicC fly PKD model responds to the antiproliferative drugs rapamycin and mimics of the second mitochondria-derived activator of caspases (Smac). Melatonin appears to be a new cyst-reducing molecule with attractive properties as a potential candidate for PKD treatment. 相似文献
34.
35.
Roman A. Polyak 《Mathematical Programming》2002,92(2):197-235
We introduce an alternative to the smoothing technique approach for constrained optimization. As it turns out for any given
smoothing function there exists a modification with particular properties. We use the modification for Nonlinear Rescaling
(NR) the constraints of a given constrained optimization problem into an equivalent set of constraints.?The constraints transformation
is scaled by a vector of positive parameters. The Lagrangian for the equivalent problems is to the correspondent Smoothing
Penalty functions as Augmented Lagrangian to the Classical Penalty function or MBFs to the Barrier Functions. Moreover the
Lagrangians for the equivalent problems combine the best properties of Quadratic and Nonquadratic Augmented Lagrangians and
at the same time are free from their main drawbacks.?Sequential unconstrained minimization of the Lagrangian for the equivalent
problem in primal space followed by both Lagrange multipliers and scaling parameters update leads to a new class of NR multipliers
methods, which are equivalent to the Interior Quadratic Prox methods for the dual problem.?We proved convergence and estimate
the rate of convergence of the NR multipliers method under very mild assumptions on the input data. We also estimate the rate
of convergence under various assumptions on the input data.?In particular, under the standard second order optimality conditions
the NR method converges with Q-linear rate without unbounded increase of the scaling parameters, which correspond to the active
constraints.?We also established global quadratic convergence of the NR methods for Linear Programming with unique dual solution.?We
provide numerical results, which strongly support the theory.
Received: September 2000 / Accepted: October 2001?Published online April 12, 2002 相似文献
36.
Sander W Roy S Polyak I Ramirez-Anguita JM Sanchez-Garcia E 《Journal of the American Chemical Society》2012,134(19):8222-8230
The phenoxyl radical 1 was generated in high yields by flash vacuum pyrolysis of allyl phenyl ether 2 with subsequent trapping of the products in argon at 3 K. In water-doped argon matrices, an OH···O complex between 1 and water is formed that could be characterized by IR spectroscopy. Several isotopomers of the complex were generated, and the IR spectra compared to results of density functional theory calculations. Other dimers between 1 and water were not found under these conditions. QM/MM calculations in simulated argon matrices reveal that an OH···π complex is unstable even at a time scale of picoseconds. This finding has implications on the related interaction between the tyrosyl radical and the water in biological systems. 相似文献
37.
Anastasiya V. Kuznetcova Ivan S. Odin Alexander A. Golovanov Iakov M. Grigorev Aleksander V. Vasilyev 《Tetrahedron》2019,75(33):4516-4530
Reaction of conjugated enynones,1,5-diarylpent-2-en-4-yn-1-ones, with malononitrile and sodium alkoxides in the corresponding alcohols at room temperature for 3–23 h results in the formation of two types of compounds (E)-/(Z)-6-aryl-4-(2-arylethenyl)-2-alkoxypyridine-3-carbonitriles (substituted nicotinonitriles), as the major reaction products in yields up to ca. 40–80%, and 6-aryl-4-arylethynyl-2-alkoxypyridines, as the minor reaction products in yields of 5–17%. Plausible mechanism of this complex and multistep reaction is discussed. The obtained pyridines possess fluorescent properties. 相似文献
38.
Iakov S. Fomenko Medhanie Afewerki Marko I. Gongola Eugene S. Vasilyev Lidia S. Shulpina Nikolay S. Ikonnikov Georgiy B. Shulpin Denis G. Samsonenko Vadim V. Yanshole Vladimir A. Nadolinny Alexander N. Lavrov Alexey V. Tkachev Artem L. Gushchin 《Molecules (Basel, Switzerland)》2022,27(13)
The reactions of CuX2 (X = Cl, Br) with dipinodiazafluorenes yielded four new complexes [CuX2L1]2 (X = Cl (1), Br (2), L1 = (1R,3R,8R,10R)-2,2,9,9-Tetramethyl-3,4,7,8,9,10-hexahydro-1H-1,3:8,10-dimethanocyclopenta [1,2-b:5,4-b’]diquinolin-12(2H)-one) and [(CuX2)2L2]n (X = Cl (3), Br (4), L2 = (1R,3R,8R,10R,1’R,3’R,8’R,10’R)-2,2,2’,2’,9,9,9’,9’-Octamethyl-1,1’,2,2’,3,3’,4,4’,7,7’,8,8’,9,9’,10,10’-hexadecahydro-1,3:1’,3’:8,10:8’,10’-tetramethano-12,12’-bi(cyclopenta [1,2-b:5,4-b’]diquinolinylidene). The complexes were characterized by IR and EPR spectroscopy, HR-ESI-MS and elemental analysis. The crystal structures of compounds 1, 2 and 4 were determined by X-ray diffraction (XRD) analysis. Complexes 1–2 have a monomeric structure, while complex 4 has a polymeric structure due to additional coordinating N,N sites in L2. All complexes contain a binuclear fragment {Cu2(μ-X)2×2} (X = Cl, Br) in their structures. Each copper atom has a distorted square-pyramidal coordination environment formed by two nitrogen atoms and three halogen atoms. The Cu-Nax distance is elongated compared to Cu-Neq. The EPR spectra of compounds 1–4 in CH3CN confirm their paramagnetic nature due to the d9 electronic configuration of the copper(II) ion. The magnetic properties of all compounds were studied by the method of static magnetic susceptibility. For complexes 1 and 2, the effective magnetic moments are µeff ≈ 1.87 and 1.83 µB (per each Cu2+ ion), respectively, in the temperature range 50–300 K, which are close to the theoretical spin value (1.73 µB). Ferromagnetic exchange interactions between Cu(II) ions inside {Cu2(μ-X)2X2} (X = Cl, Br) dimers (J/kB ≈ 25 and 31 K for 1 and 2, respectively) or between dimers (θ′ ≈ 0.30 and 0.47 K for 1 and 2, respectively) were found at low temperatures. For compounds 3 and 4, the magnetic susceptibility is well described by the Curie–Weiss law in the temperature range 1.77–300 K with µeff ≈ 1.72 and 1.70 µB for 3 and 4, respectively, and weak antiferromagnetic interactions (θ ≈ −0.4 K for 3 and −0.65 K for 4). Complexes 1–4 exhibit high catalytic activity in the oxidation of alkanes and alcohols with peroxides. The maximum yield of cyclohexane oxidation products reached 50% (complex 3). Based on the data on the study of regio- and bond-selectivity, it was concluded that hydroxyl radicals play a decisive role in the oxidation reaction. The initial products in reactions with alkanes are alkyl hydroperoxides. 相似文献
39.
The ultraviolet absorption spectra, the optical activity and the reference index of solutions of glucose, sucrose, and maltose prepared from irradiated powders were investigated. 相似文献
40.
Whole-cell luminescent bioreporter sensors based on immobilized recombinant Escherichia coli are described and evaluated. The sensors were prepared by glutaraldehyde-anchoring of nonspecific anti-E. coli antibodies on aminosylilated gold or silica glass surfaces with subsequent attachment of the probe bacteria. We demonstrate the generality of the concept by attachment of several E. coli strains that express luciferase in response to different physiological stress conditions including heat shock, DNA damage (SOS), fatty acid availability, peroxide and oxidative stress. The sensors can be used either as single- or multiple-use disposable sensing elements or for continuous operation. We show compatibility with optical fiber technology. Storage stability of the sensors exceeded 5 months with no measurable deterioration of the signal. Repeatability on exposure in successive days was <15%, as was sensor to sensor reproducibility. Sensitivity and detection limits of the immobilized cells were comparable to that of non-immobilized bacteria. 相似文献