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排序方式: 共有172条查询结果,搜索用时 15 毫秒
41.
Manuela Jörg Mark Agostino Elizabeth Yuriev Frankie S. Mak Neil D. Miller Jonathan M. White Peter J. Scammells Ben Capuano 《Structural chemistry》2013,24(4):1241-1251
Herein, we describe the synthesis of the adenosine A2A antagonist ZM 241385 (9) starting from commercially available 2-furanhydrazide (1) and including a comprehensive structural characterization of all the intermediates and the final product. In addition, extensive NMR analysis, including temperature and concentration-dependent experiments, are reported as well as the first single-crystal structure of the compound ZM 241385 (9) as the trihydrate. Furthermore, an extensive structural comparison of the single-crystal structure with the published protein bound X-ray structures is reported. 相似文献
42.
Ruthenium‐Catalyzed Cross‐Dehydrogenative ortho‐N‐Carbazolation of Diarylamines: Versatile Access to Unsymmetrical Diamines 下载免费PDF全文
Marie‐Laure Louillat Agostino Biafora Fabien Legros Prof. Dr. Frederic W. Patureau 《Angewandte Chemie (International ed. in English)》2014,53(13):3505-3509
The dehydrogenative C–N cross‐coupling of unprotected, secondary anilines through ortho‐N‐carbazolation has been achieved using a Ru catalytic system with O2 as the terminal oxidant. The reactions proceed in an intermolecular fashion, selectively in the ortho position. Implications for the field of organic synthesis are discussed. 相似文献
43.
Alois Bonifacio Silvia Dalla Marta Riccardo Spizzo Silvia Cervo Agostino Steffan Alfonso Colombatti Valter Sergo 《Analytical and bioanalytical chemistry》2014,406(9-10):2355-2365
Surface-enhanced Raman spectroscopy (SERS) is a good candidate for the development of fast and easy-to-use diagnostic tools, possibly used on biofluids in point-of-care or screening tests. In particular, label-free SERS spectra of blood serum and plasma, two biofluids widely used in diagnostics, could be used as a metabolic fingerprinting approach for biomarker discovery. This study aims at a systematic evaluation of SERS spectra of blood serum and plasma, using various Ag and Au aqueous colloids, as SERS substrates, in combination with three excitation lasers of different wavelengths, ranging from the visible to the near-infrared. The analysis of the SERS spectra collected from 20 healthy subjects under a variety of experimental conditions revealed that intense and repeatable spectra are quickly obtained only if proteins are filtered out from samples, and an excitation in the near-infrared is used in combination with Ag colloids. Moreover, common plasma anticoagulants such as EDTA and citrate are found to interfere with SERS spectra; accordingly, filtered serum or heparin plasma are the samples of choice, having identical SERS spectra. Most bands observed in SERS spectra of these biofluids are assigned to uric acid, a metabolite whose blood concentration depends on factors such as sex, age, therapeutic treatments, and various pathological conditions, suggesting that, even when the right experimental conditions are chosen, great care must be taken in designing studies with the purpose of developing diagnostic tests. 相似文献
44.
This paper proposes and illustrates a new perturbed gamma degradation process where the measurement error is modeled as a non‐Gaussian random variable that depends stochastically on the actual degradation level. The expression of the likelihood function for a generic set of noisy degradation measurements is derived, and the expression of the remaining useful life distribution of a degrading unit that fails when its degradation level exceeds a given threshold limit is formulated. A particle filter method is suggested, which allows one to compute the likelihood function and to estimate the remaining useful life distribution in a quick yet efficient manner. In addition, a closed‐form approximation of the perturbed gamma process is proposed to use in the special, yet meaningful, case where the standard deviation of the measurement error depends linearly on the actual degradation level. Finally, an applicative example is discussed, where the parameters of the perturbed gamma process, the remaining useful life distribution, and the mean remaining useful life of the degrading units are estimated from a set of noisy real degradation data. 相似文献
45.
46.
James R HancockP.A D’Agostino 《Analytica chimica acta》2002,457(1):71-82
The chemical/biological (CB) threat spectrum encompasses a wide range of potential agents including chemical warfare agents, biological warfare agents and toxins of biological origin that fall between these two main agent categories. These proteinaceous and non-proteinaceous toxins, commonly referred to as mid-spectrum agents, range in molecular mass from a few hundred to more than a hundred thousand daltons. The large number of potential candidates as well as the structural diversity of possible mid-spectrum agents makes identification of these compounds a challenge. The NATO defense community has recognized these challenges and has a working group that is developing identification protocols and evaluating methods through a series of international analytical exercises. Identification strategies rely heavily on recent advances that have been made in both mass spectrometry (MS) and liquid chromatography (LC), with LC-MS typically being employed as the primary method for separation/identification. While this paper focuses on the application of these and related instrumental analytical techniques for the identification of mid-spectrum agents, the approach described could be applied in the fields of toxicology, forensic science and environmental analysis. Areas for future research have been identified and application of developed mid-spectrum identification methods to the ongoing biological and toxin weapons convention (BTWC) are anticipated. 相似文献
47.
Politano A Agostino RG Colavita E Formoso V Chiarello G 《The Journal of chemical physics》2007,126(24):244712
Collective electronic excitations occurring in Na layers grown on Cu(111) and in H2O/Na/Cu(111) have been investigated at room temperature by high resolution electron energy loss spectroscopy. Loss spectra taken for a coverage between 0.55 and 0.70 ML of Na are characterized by a feature at 3.0 eV assigned to a Mie resonance. Further increasing the Na coverage leads to the appearance of the Na surface plasmon at 3.9 eV. Water molecules dissociate on Na layers as shown by the appearance of the OH-Na vibration. Upon water adsorption, relevant effects on both electronic excitations and vibrational modes were observed as a function of Na coverage. 相似文献
48.
The cubic and the quartic semidiagonal anharmonic force fields of naphthalene-h8 and -d8 are obtained using density functional theory (DFT) with the B9-71 functional and a triple-zeta plus double polarization (TZ2P) basis set. The fundamental frequencies computed by second-order vibrational perturbation theory are in very good agreement with the experimental data, with a mean absolute deviation (MAD) of 4 cm(-1) for C(10)H(8) and 6 cm(-1) for C(10)D(8). Some of the fundamental frequencies have been reassigned on the basis of the present results. Only CH stretchings seem to be significantly affected by Fermi resonances, with two shifts larger than 10 cm(-1). Calculated infrared harmonic intensities reproduce the experimental data within 15%, with the exception of CH stretchings affected by a larger error. Scale factors from C(10)H(8) have been tested by deriving the fundamental frequencies of C(10)D(8) from the theoretical harmonic ones. These fundamentals are in nice agreement with those obtained from the C(10)D(8) anharmonic force field. These results support the use of scale factors to calculate the vibration spectra of larger polycyclic aromatic hydrocarbons of great astrophysical interest. 相似文献
49.
Marco Di Luzio Massimo Oddone Michele Prata Daniele Alloni Giancarlo D’Agostino 《Journal of Radioanalytical and Nuclear Chemistry》2017,312(1):75-80
In this paper, evaluation of neutron flux parameters of TRIGA Mark II reactor in Pavia was carried out. For any of the three irradiation positions investigated, this work represented the first experimental evaluation of α. Moreover, in addition to α, values of other parameters such as f, Φ th and Φ e were also calculated and compared with the existent literature data from other TRIGA Mark II reactors and the Pavia’s facility. Results obtained in the present study represent a mandatory step ahead for future application of k 0-Neutron Activation Analysis method (k 0-NAA) at Pavia’s facility. 相似文献
50.
Catalytic Decarboxylative Cross‐Coupling of Aryl Chlorides and Benzoates without Activating ortho Substituents 下载免费PDF全文
Jie Tang Agostino Biafora Prof. Dr. Lukas J. Goossen 《Angewandte Chemie (International ed. in English)》2015,54(44):13130-13133
The restriction of decarboxylative cross‐coupling reactions to ortho‐substituted or heterocyclic carboxylate substrates was overcome by holistic optimization of a bimetallic Cu/Pd catalyst system. The combination of a CuI/Me4phen decarboxylation catalyst and a [(MeCN)4Pd](OTf)2/XPhos cross‐coupling catalyst enables the synthesis of biaryls from inexpensive aryl chlorides and potassium benzoates regardless of their substitution pattern. 相似文献