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211.
212.
Carlucci L Ciani G Maggini S Proserpio DM Visconti M 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(41):12328-12341
The modular engineering of heterometallic nanoporous metal-organic frameworks (MOFs) based on novel tris-chelate metalloligands, prepared using the functionalised β-diketone 1,3-bis(4'-cyanophenyl)-1,3-propanedione (HL), is described. The complexes [M(III)L(3)] (M=Fe(3+), Co(3+)) and [M(II)L(3)](NEt(4)) (M=Mn(2+), Co(2+), Zn(2+), Cd(2+)) have been synthesised and characterised, all of which exhibit a distorted octahedral chiral structure. The presence of six exo-oriented cyano donor groups on each complex makes it a suitable building block for networking through interactions with external metal ions. We have prepared two families of MOFs by reacting the metalloligands [M(III)L(3)] and [M(II)L(3)](-) with many silver salts AgX (X=NO(3)(-), BF(4)(-), PF(6)(-), AsF(6)(-), SbF(6)(-), CF(3)SO(3)(-), tosylate), specifically the [M(III)L(3)Ag(3)]X(3)·Solv and [M(II)L(3)Ag(3)]X(2)·Solv network species. Very interestingly, all of these network species exhibit the same type of 3D structure and crystallise in the same trigonal space group with similar cell parameters, in spite of the different metal ions, ionic charges and X(-) counteranions of the silver salts. We have also succeeded in synthesising trimetallic species such as [Zn(x)Fe(y)L(3)Ag(3)](ClO(4))((2x+3y))·Solv and [Zn(x)Cd(y)L(3)Ag(3)](ClO(4))(2)·Solv (with x+y=1). All of the frameworks can be described as sixfold interpenetrated pcu nets, considering the Ag(+) ions as simple digonal spacers. Each individual net is homochiral, containing only Δ or Λ nodes; the whole array contains three nets of type Δ and three nets of type Λ. Otherwise, taking into account the presence of weak Ag-C σ bonds involving the central carbon atoms of the β-diketonate ligands of adjacent nets, the six interpenetrating pcu networks are joined into a unique non-interpenetrated six-connected frame with the rare acs topology. The networks contain large parallel channels of approximate hexagonal-shaped sections that represent 37-48% of the cell volume and include the anions and many guest solvent molecules. The guest solvent molecules can be reversibly removed by thermal activation with retention of the framework structure, which proved to be stable up to about 270°C, as confirmed by TGA and powder XRD monitoring. The anions could be easily exchanged in single-crystal to single-crystal processes, thereby allowing the insertion of selected anions into the framework channels. 相似文献
213.
Federica Bianchi Monica Mattarozzi Maria Careri Alessandro Mangia Marilena Musci Francesca Grasselli Simona Bussolati Giuseppina Basini 《Analytical and bioanalytical chemistry》2010,396(7):2639-2645
A simple and easily automable method based on solid-phase microextraction followed by gas chromatographic–mass spectrometric
analysis was developed for the determination of two potential angiogenesis modulators 17β-estradiol (17-BE) and 2-methoxyestradiol
(2-MEOE) in culture media. Trifluoroacetic anhydride was used as the derivatising agent. A homemade octadecyl silica coating,
characterised by a coating thickness of 72 ± 10 μm and a good thermal stability until 250 °C, was prepared. Experimental design
was used to optimise the extraction conditions in terms of derivatisation time, derivatisation temperature and time of extraction.
As for method validation, lower limits of quantification of 0.17 and 0.015 μg/l for 17β-estradiol and 2-methoxyestradiol,
respectively, were obtained. Finally, the capabilities of the developed fibres were evaluated for the analysis of the investigated
analytes developed by granulosa cells in culture media maintained under normoxic, hypoxic and anoxic conditions, in order
to better elucidate their possible role in the angiogenic process. An increase of the production of both 17-BE and 2-MEOE
in hypoxic and anoxic conditions seems to be related to the effect of oxygen deprivation. 相似文献
214.
215.
Francese S Lambardi D Mastrobuoni G la Marca G Moneti G Turillazzi S 《Journal of the American Society for Mass Spectrometry》2009,20(1):112-123
A new analytical approach using matrix-assisted laser desorption/ionization mass spectrometry imaging (MALDI MSI) for the study of honeybee venom is shown. In vitro and in vivo models simulating the bee sting have been developed using live honeybees and, as the envenomation sites, pig ears and rat legs; MALDI MSI has been used to map, over time, the diffusion and distribution of three venom allergens (Api m 1, Api m 4, and Api m 6) and two venom toxins (apamine and mast cell degranulating peptide). In conjunction with other classical biochemical techniques and high resolution mass spectrometry (HRMS), structural data have been obtained that contribute to current understanding of honeybee venom composition. Initial data have also been obtained demonstrating the feasibility of mapping the organism's response to the sting. The opportunity to monitor venom diffusion and the organism's response at the same time might open new pathways for in vivo preclinical studies in designing and testing new venom immunotherapy (VIT). 相似文献
216.
Elide A. Pastorello Laura Farioli Valerio Pravettoni Joseph Scibilia Amedeo Conti Donatella Fortunato Linda Borgonovo Simona Bonomi Laura Primavesi Barbara Ballmer-Weber 《Analytical and bioanalytical chemistry》2009,395(1):93-102
Italian patients with maize anaphylaxis have been shown to have IgE toward two major maize allergens: an alpha-amylase inhibitor
and a 9-kDa LTP. A complete study on maize food allergens in patients with positive maize double-blind, placebo-controlled
food challenge (DBPCFC) is lacking. The objective was to utilize the three maize protein fractions to identify and characterize
the most relevant IgE-binding proteins recognized by the sera of Italian and Swiss patients with either a positive maize-DBPCFC
or a history of maize-induced anaphylaxis. Osborne’s protein fractions of maize were extracted to obtain water-soluble, total
zein, and total protein fractions. Protein IgE-binding capacity was investigated by SDS-PAGE immunoblotting using the sera
from DBPCFC-positive patients and from patients with maize-induced anaphylaxis. Purified maize LTP was used to inhibit the
IgE immunoblotting of the three protein fractions. IgE immunoblotting demonstrated that the 9-kDa LTP was recognized by all
the Italian patients and by none of the Swiss patients. Other allergens were: 14-kDa α-amylase inhibitor, 30-kDa endochitinases
A and -B, 19 kDa zein-β precursor, and 26 kDa zein-α precursor; a newly described allergen, the globulin-2 precursor, identified in the total protein fraction. It is
noteworthy that maize LTP and endochitinase were cross-reactive with grape LTP and one grape endochitinase. LTP was found
to be the only major allergen in Italian patients with either positive maize challenge or a history of maize-induced anaphylaxis.
We have identified other maize allergens in subjects with maize food allergy, as grape cross-reactive endochitinase, however,
the clinical significance of these proteins needs to be investigated in larger groups of patients with allergy to these food
items. 相似文献
217.
This article presents the vibration action on the human body found in a tram travel, where made the vibration measurements. Also presented a mathematical model with two degrees of freedom. Finally a comparison was made between the results obtained from measurements and the results of integration. (© 2011 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
218.
Bonini M Rossi S Karlsson G Almgren M Lo Nostro P Baglioni P 《Langmuir : the ACS journal of surfaces and colloids》2006,22(4):1478-1484
In this article, we report evidence of beta-cyclodextrin (beta-CD) self-aggregation in water. A critical aggregation concentration (cac) between 2 and 3 mM was determined by using dynamic (DLS) and static (SLS) light scattering to investigate the presence of beta-cyclodextrin aggregates. Transmission electron microscopy at cryogenic temperature (Cryo-TEM) was used to detect the structural features of cyclodextrin self-aggregates. The results show the occurrence of polymorphism depending on the beta-CD concentration: polydisperse nearly spherical objects with diameters of about 100 nm are present at lower concentrations, whereas micrometer planar aggregates are predominant at higher concentrations. 相似文献
219.
Gómez-García CJ Coronado E Curreli S Giménez-Saiz C Deplano P Mercuri ML Pilia L Serpe A Faulmann C Canadell E 《Chemical communications (Cambridge, England)》2006,(47):4931-4933
The novel paramagnetic and chiral anion [Fe(C5O5)3]3- has been combined with the organic donor BEDT-TTF (= ET = bis(ethylenedithio)tetrathiafulvalene) to yield the first chirality-induced alpha phase and a paramagnetic metal. 相似文献
220.
Rosu T Pasculescu S Lazar V Chifiriuc C Cernat R 《Molecules (Basel, Switzerland)》2006,11(11):904-914
The synthesis of Cu(II) complexes derived from Schiff base ligands obtained by the condensation of 2-hydroxybenzaldehyde or terephtalic aldehyde with 4-amino-antipyrine (4-amino-2,3-dimethyl-1-phenyl-3-pyrazolin-5-one) is presented. The newly prepared compounds were characterized by( 1)H-NMR, UV-VIS, IR and ESR spectroscopy. The determination of the antimicrobial activity of the ligands and of the complexes was carried out on samples of Escherichia coli, Klebsiella pneumoniae, Acinetobacter boumanii, Pseudomonas aeruginosa, Staphylococcus aureus and Candida sp. The qualitative and quantitative antimicrobial activity test results proved that all the prepared complexes are very active, especially against samples of Ps. aeruginosa, A. Boumanii, E. coli and S. aureus. 相似文献